explanation blue bibcodes open ADS page with paths to full text
Author name code: pasachoff
ADS astronomy entries on 2022-09-14
author:"Pasachoff, Jay M."
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Title: The Eclipse Megamovie Project (2017)
Authors: Hudson, Hugh S.; Peticolas, Laura; Johnson, Calvin; White,
Vivian; Bender, Mark; Pasachoff, Jay M.; Martínez Oliveros, Juan
Carlos; Collier, Braxton; Filippenko, Alexei V.; Filippenko, Noelle;
Fraknoi, Andrew; Guevara Gómez, Juan Camilo; Koh, Justin; Konerding,
David; Krista, Larisza; Kruse, Brian; McIntosh, Scott; Mendez, Brian;
Ruderman, Igor; Yan, Darlene; Zevin, Dan
2022arXiv220713704H Altcode:
The total solar eclipse of August 21, 2017, crossed the whole width
of North America, the first occasion for this during the modern age
of consumer electronics. Accordingly, it became a great opportunity
to engage the public and to enlist volunteer observers with relatively
high-level equipment; our program ("Eclipse Megamovie") took advantage
of this as a means of creating a first-ever public database of such
eclipse photography. This resulted in a large outreach program,
involving many hundreds of individuals, supported almost entirely
on a volunteer basis and with the institutional help of Google, the
Astronomical Society of the Pacific, and the University of California,
Berkeley. The project home page is \url{http://eclipsemegamovie.org},
which contains the movie itself. We hope that our comments here will
help with planning for similar activities in the total eclipse of
April 8, 2024.
---------------------------------------------------------
Title: Centennial of Definitive Verification of Einstein's GR:
1922-2022
Authors: Pasachoff, Jay
2022AAS...24023601P Altcode:
Two years ago, we celebrated (AAS meeting 235 session 001) the
centennial of the "Eddington expeditions" whose reports at meetings
of the Royal Astronomical Society and the Royal Society in late 1919
brought Einstein's General Theory of the Relativity to the scientific
and nonscientific world, and made Einstein a figure not only in science
but also in Popular Culture. A Lick Observatory expedition in 1922 led
to even better results on the observational agreement with Einstein's
theory. We devote this special centennial session to discussing the
Lick expedition and the artifacts that survive, to the role of the
expedition in scientific history, similar observations made at the
2017 Great American Eclipse and plans for similar eclipse-deflection
observations planned for the April 8, 2024, total solar eclipse to
be observed probably from Mexico before the eclipse path enters the
United States.
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Title: Preliminary Report on the December 4, 2021, Solar Eclipse
Antarctic Expeditions
Authors: Pasachoff, Jay; Boris, Theo; Lockwood, Christian; Sliski,
David; Voulgaris, Aristeidis; Schneider, Glenn; Knowlton, Peter;
Tosolini, Anna; Lu, Muzhou; Economou, Thanasis; Rojo, Patricio
2022AAS...24033209P Altcode:
We give a preliminary report on results gathered from our three
successful expeditions to the December 4, 2021, total solar eclipse,
whose totality passed over Antarctica and adjacent ocean. One of
our groups was on a chartered LATAM Boeing 787 Dreamliner that
flew eastward from Punta Arenas, Chile at 41,000 ft (a second 787
was 1000 feet lower). Eastward of the Falkland Islands the aircraft
turned southwest for a totality run as the upper of two planes with
paths plotted by Glenn Schneider to observe totality a few degrees
above the horizon out the left-hand windows from near the sunrise
point. Our group carried cameras with telephotos and 3 spectrographs
from Voulgaris (Icarus Optomechanics), and observed a measured 1 m
52 s of totality (07:22:35.1 to 07:04:26.6 UTC; middle of eclipse:
07:03:30.85 -56.167825°S -45.209159°W). We also worked with four
people including Boris, Lockwood, and equipment, who flew to Union
Glacier, on the Antarctic continent (Latitude -79.76, Longitude
-82.85). In addition to astronomical equipment to image totality
at an altitude of about 14° above the horizon, they sent back a
livestream to NASA.gov and the NASA YouTube channel. Further, Rojo, a
professor of astronomy at the University of Chile, joined the official
expedition carried by the Chilean Air Force to spend two weeks on Union
Glacier, Antarctica, conducting that expedition's only astronomical
observations. He carried Celestron, Sony, Canon, and Nikon telephotos;
with Sony, Nikon, and Canon cameras, much of the equipment from Williams
College; with filters by Questar and Thousand Oaks Optical; and an
Icarus Optomechanics spectrograph from Voulgaris. <P />In addition,
efforts by the AAS Eclipse Task Force's Formal Education working group
are on-going, in preparation for the annular 2023 and total 2024 solar
eclipses. <P />JMP's current research about eclipses is sponsored by
grant AGS-1903500 of the Solar Terrestrial Program, Atmospheric and
Geospace Sciences Division of the NSF, succeeding AGS-1602461 from the
period of the 2017 eclipse. We thank Williams College for additional
student expeditionary support from the Freeman Foote endowment. We
thank Tim Todd of TEI Tours and Travel, for his travel arrangements;
John Beattie for on-site arrangements, and Mark Sood of A Classic
Tours Collection for additional assistance.
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Title: A Diligent Analysis of the Flash and Coronal Spectrum of the
Total Solar Eclipse of 20 March 2015
Authors: Voulgaris, Aristeidis G.; Mouratidis, C.; Tziotziou, K.;
Seiradakis, J. H.; Pasachoff, J. M.
2022SoPh..297...49V Altcode:
During totality of the solar eclipse of 20 March 2015, at Svalbard,
Norway, the emission spectra of the solar chromosphere and corona were
captured with a slitless spectrograph. A very lucky coincidence of a
large number of sunspots and Active Regions (ARs) around the solar limb
allowed us to observe a number of different spectroscopic effects. This
eclipse took place about one year after the second solar maximum of the
double-peaked Solar Cycle 24, which produced less activity than the
previous stronger solar maxima. The spectra taken during the eclipse
show strong and high activity of the green coronal line Fe XIV (5303 Å)
and the lower intensity of the red coronal line Fe X (6374 Å). After
subtraction of the emitted continuum of K+(F) corona, the detection
and identification of several extremely weak emission lines, including
the two forbidden emission lines of Ca XV (5694 Å and 5446 Å) and
also Ni XIII (5116 Å) and Ni XV (6702 Å), was possible. The large
number of ARs also led to the observation of a continuum brightening
in ARs and a continuum darkening in surrounding areas.
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Title: IAU Commission C3 (History of Astronomy): Triennial Report,
2018–2021
Authors: Orchiston, Wayne; Sterken, Christiaan; Schechner, Sara;
Sun, Xiaochun; Chinnici, Ileana; Lee, Eun-Hee; Pasachoff, Jay M.;
van der Kruit, Pieter C.
2022JAHH...25..138O Altcode:
IAU Commission C3 (History of Astronomy) started in 2015 as a natural
continuation of the previous IAU Commission 41 for History of Astronomy
which was established in 1948 and which was extremely successful
in supporting research on the history of astronomy, organizing and
sponsoring workshops and conferences, promoting research collaborations,
forming specialist working groups and fostering the publication of
members' research (see Kochhar et al., 2015).
---------------------------------------------------------
Title: White-Light Coronal Imaging at the 21 August 2017 Total
Solar Eclipse
Authors: Pasachoff, Jay M.; Rušin, Vojtech
2022SoPh..297...28P Altcode:
We describe the solar corona as imaged in the 21 August 2017 total solar
eclipse from sites in Oregon and Illinois, USA separated by nearly one
hour. Our composite images, each made from dozens of individual frames,
show helmet streamers, nearly radially oriented narrow rays, and polar
coronal holes filled with polar plumes. The Ludendorff flattening index
of 0.24 is compared with measurements from the last two centuries. We
discuss the most remarkable coronal dynamics detected over a nearly
one-hour interval between the two observing sites.
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Title: The Fiftieth Anniversary Celebration of the Solar Physics
Division of the American Astronomical Society
Authors: Pasachoff, Jay M.; Dupree, Andrea K.; Foukal, Peter; Weart,
Spencer; Zirker, Jack
2021JAHH...24.1057P Altcode:
The fiftieth anniversary celebration of the Solar Physics Division
of the American Astronomical Society was held virtually in August
2020 with joint sponsorship from the Historical Astronomy Division,
following the COVID-19-forced transformation of the original plan to
hold the meeting in Spokane, Washington. The presenters had given
papers at the first meeting in Huntsville, Alabama, in 1970, and
addressed related fields from the vantage point of fifty years.
---------------------------------------------------------
Title: The eclipse Megamovie Project (2017)
Authors: Hudson, Hugh; Peticolas, Laura; Johnson, Calvin; White,
Vivian; Bender, Mark; Pasachoff, Jay M.; Oliveros, Juan Carlos
Martínez; Filippenko, Alexei V.; et al.
2021JAHH...24.1080H Altcode:
The total solar eclipse of August 21, 2017, crossed the whole width
of North America, the first occasion for this during the modern age
of consumer electronics. Accordingly, it became a great opportunity
to engage the public and to enlist volunteer observers with relatively
high-level equipment; our program ('Eclipse Megamovie') took advantage
of this as a means of creating a first-ever public database of
such eclipse photography. This resulted in a large outreach program,
involving more than one thousand individuals, supported almost entirely
on a volunteer basis and with the institutional help of Google, the
Astronomical Society of the Pacific, and the University of California,
Berkeley. The project home page at eclipsemegamovie.org contains
the finished movie itself. We hope that our comments here will help
with planning for similar activities during the total eclipse of 8
April 2024.
---------------------------------------------------------
Title: Total solar eclipses then and now
Authors: Pasachoff, Jay M.
2021JAHH...24.1069P Altcode:
I describe the new equipment and observations of the major total solar
eclipse that passed from Mexico (where we observed it, in Miahuatlán,
Oaxaca) on 7 March 1970, to the improved imaging and other capabilities
we applied to the recent total solar eclipses of 2 July 2019 (from
Chile), and 4 December 2021 (from on and near Antarctica, including
airborne observations).
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Title: Another 6-Inch Brashear Restoration II
Authors: Pasachoff, Jay M.
2021S&T...142a...6P Altcode:
No abstract at ADS
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Title: Observational Validation of Predictions for the 2020 Eclipse
Corona
Authors: Pasachoff, J. M.; Downs, C.; Linker, J.; Caplan, R.; Riley,
P.; Lionello, R.; Möller, A.; Rušin, V.; Vanur, R.; Carlos, W.
2021AAS...23822901P Altcode:
Using observations from Argentina during the eclipse of 14 December
2020, compare our observations to a prediction simulation of the
eclipse corona, developed by Predictive Science Inc. This 2020
prediction was based on a thermodynamic magnetohydrodynamic (MHD)
model of the corona with a new two-temperature formulation and updates
to a wave-turbulence-driven (WTD) heating and acceleration model. A
comparison of the observed and predicted white light morphology
is used to assess and inform the WTD model parametrization. Using
observations by AM from Piedra del Águila, Argentina, we provided a
quick composite by Williams College for comparison with the Predictive
Science prediction for a NASA press release the following day (<A
href="https://www.nasa.gov/feature/goddard/2020/scientists-use-nasa-data-predict-appearance-corona-dec-14-total-solar-eclipse">https://www.nasa.gov/feature/goddard/2020/scientists-use-nasa-data-predict-appearance-corona-dec-14-total-solar-eclipse</A>)
and a later composite by RV for a NASA press
release about a newly discovered sungrazer comet that soon followed (<A
href="https://www.nasa.gov/feature/goddard/2020/recently-discovered-comet-seen-during-2020-total-solar-eclipse-SOHO">https://www.nasa.gov/feature/goddard/2020/recently-discovered-comet-seen-during-2020-total-solar-eclipse-SOHO</A>).
See also Pasachoff, Jay M., 2021, Preliminary Report on the 14
December 2020 Total Solar Eclipse Observations, for International
Astronomical Union Symposium 367: Education and Heritage in the Era of
Big Data in Astronomy, submitted (Cambridge University Press, 2021);
Pasachoff, Jay M., 2021, The 2020 Total Eclipse, Astronomy Magazine,
April, pp. 47-51. Acknowledgments: JMP's research for this eclipse
was sponsored by grant AGS-1903500 of the Solar Terrestrial Program,
Atmospheric and Geospace Sciences Division of the NSF. PSI was supported
by AFOSR, NASA, and NSF. VR and RV have been supported by the project
VEGA ~ 2/0048/20 (Slovak Academy of Sciences). We thank Lina Tran and
Joy Ng of NASA's Goddard Space Flight Center for their work on the
prediction/verification and eclipse-comet press releases.
---------------------------------------------------------
Title: High-frequency Forbidden-line Coronal Oscillations As a Test
of Coronal Heating Methods
Authors: Pasachoff, J. M.; Person, M. J.; Wang, A.
2021AAS...23822902P Altcode:
We report on data reduction carried out in 2020 on high-frequency
(2 Hz) observations in the coronal green line (Fe XIV, 637.4 nm)
and the coronal red line (Fe X, 530.3 nm) at the Williams College
solar eclipse expedition to Salem, Oregon, for the August 21, 2017,
totality. The observations and analysis followed previous work, testing
the predictions of coronal heating from surface Alfvén waves, which
would be at much higher frequency than the body waves in coronal loops
usually invoked and studied. AW, in his A.B. senior thesis with joint
advisors in the Astronomy and Mathematics departments, computed power
spectra. He found some excess power at the high frequencies but only
in the pixels closest to the solar limb, raising questions of equipment
vibrations, raising questions for further observations. Newly designed
equipment, with new detectors, was built for the 14 December 2020 total
solar eclipse, but COVID-19-related travel bans at Williams College
and at MIT prevented us from taking the apparatus. We look forward to
using it at the total solar eclipses of 2023 in Australia and 2024 in
Mexico/US. <P />Acknowledgments: Our research has been supported in
large part from grant AGS-1903500 from the Solar Terrestrial Program
of the Atmospheric and Geospace Sciences Division of the National
Science Foundation and prior NSF grants, and from the Committee for
Research and Exploration of the National Geographic Society, with
additional support from Sigma Xi. Additional support for undergraduate
participation came from the NSF, the NASA Massachusetts Space Grant
Consortium, and the Clare Booth Luce Foundation, with travel support
from the Freeman Foote Fund, the Rob Spring Fund, the Brandi Fund,
and other sources at Williams College.
---------------------------------------------------------
Title: The International Astronomical Union's Working Group on
Solar Eclipses
Authors: Pasachoff, J. M.
2021AAS...23822903P Altcode:
The International Astronomical Union's Working Group on Solar Eclipses
of Divisions C (Education, Outreach, and Heritage) and E (Sun and
Heliosphere) has the following tasks: (a) Working with the general
public, providing materials and links to explain why eclipses are
interesting to watch, how to observe them safely, and what science
is being studied; and (b) Working with professional astronomers
from around the world, to help coordinate their expeditions to
total solar eclipses, including helping them work with customs in
various countries about the temporary importation of scientific
equipment. With our especially easy-to-remember website URL of <A
href="http://eclipses.info">http://eclipses.info</A>, we endeavor
to be a one-stop location for a wide variety of observing aids for
professional and amateur astronomers. We link, for example, to the
major sites for eclipse mapping. For professionals, we hope to be able
to advise on the temporary duty-free import of equipment for eclipse
observations. We provide links to books and summary articles about
solar eclipses, and information about safe observing of solar eclipses
(while trying to explain their excitement and value to the general
public). • Members: Jay Pasachoff (USA, Chair), Iraida Kim (Russia),
Jagdev Singh (India), Vojtech Rusin (Slovakia, through 2021), Yoichiro
Hanaoka (Japan), Zhongquan Qu (China), Beatriz Garcia (Argentina),
Patricio Rojo (Chile), Xavier Jubier (France), Fred Espenak (US), Jay
Anderson (Canada), Glenn Schneider (US), Michael Gill (UK), Michael
Zeiler (USA), Bill Kramer (USA); associates: Michael Kentrianakis
(USA), and Ralph Chou (Canada). • For the 2019 and 2020 total
eclipses in Chile and Argentina, Patricio Rojo (U. Chile) and Beatriz
Garcia (Pierre Auger Observatory, Argentina) were added to the Working
Group.• For the next triennium, September 2021-September 2024, given
visibility of totality from Learmonth, Western Australia in 2023, we
propose adding Terry Cuttle (public outreach, Australia) and Michael
Wheatland (U. Sydney; an editor of the journal Solar Physics). We
also propose adding Andreas Möller (Germany; who will collaborate
with Bill Kramer on an archive of eclipse publications and maintain
the eclipse-chaser.com website). Prof. Wheatland is an IAU member;
Mr. Cuttle and Mr. Möller would be associates. Also we add Costantino
Sigismondi (Italy), Robert Walsh (UK), and Kevin Reardon (US National
Solar Observatory, USA). For the three eclipses in Spain (two total
and one annular) in 2025-2026-2017, we add Mohamad Soltanolkotabi
(Spain). We also look ahead to eclipses in Australia in 2028 and
2030. The 2027 eclipse continues from Spain across North Africa. The
2030 eclipse that reaches Australia starts over South Africa. • JMP
represents this IAU Working Group on the American Astronomical Society's
Solar Eclipse Task Force for the 2023 and 2024 eclipses (see <A
href="http://eclipse.aas.org">http://eclipse.aas.org</A>): Solar Eclipse
Across America. Each year, we provide "Eclipses" for the International
Geophysical Calendar (International Space Environmental Service), <A
href="http://www.spaceweather.org/ISES/info/geocal/geocal.html">http://www.spaceweather.org/ISES/info/geocal/geocal.html</A>
• Acknowledgment: JMP's current solar eclipse activity is sponsored
in large part by grant 1903500 of the Solar Terrestrial Program,
Atmospheric and Geospace Sciences Division, NSF.
---------------------------------------------------------
Title: Haze in Pluto's atmosphere: Results from SOFIA and ground-based
observations of the 2015 June 29 Pluto occultation
Authors: Person, Michael J.; Bosh, Amanda S.; Zuluaga, Carlos A.;
Sickafoose, Amanda A.; Levine, Stephen E.; Pasachoff, Jay M.; Babcock,
Bryce A.; Dunham, Edward W.; McLean, Ian S.; Wolf, Jürgen; Abe,
Fumio; Becklin, E. E.; Bida, Thomas A.; Bright, Len P.; Brothers,
Tim; Christie, Grant; Durst, Rebecca F.; Gilmore, Alan C.; Hamilton,
Ryan T.; Harris, Hugh C.; Johnson, Chris; Kilmartin, Pamela M.;
Kosiarek, Molly; Leppik, Karina; Logsdon, Sarah E.; Lucas, Robert;
Mathers, Shevill; Morley, C. J. K.; Nelson, Peter; Ngan, Haydn;
Pfüller, Enrico; Natusch, Tim; Sallum, Stephanie; Savage, Maureen L.;
Seeger, Christina H.; Siu, Ho Chit; Stockdale, Chris; Suzuki, Daisuke;
Thanathibodee, Thanawuth; Tilleman, Trudy; Tristram, Paul J.; Vacca,
William D.; Van Cleve, Jeffrey; Varughese, Carolle; Weisenbach,
Luke W.; Widen, Elizabeth; Wiedemann, Manuel
2021Icar..35613572P Altcode:
On UT 29 June 2015, the occultation by Pluto of a bright star (r‧ =
11.9) was observed from the Stratospheric Observatory for Infrared
Astronomy (SOFIA) and several ground-based stations in New Zealand and
Australia. Pre-event astrometry allowed for an in-flight update to the
SOFIA team with the result that SOFIA was deep within the central flash
zone (~22 km from center). Analysis of the combined data leads to the
result that Pluto's middle atmosphere is essentially unchanged from
2011 and 2013 (Person et al. 2013; Bosh et al. 2015); there has been no
significant expansion or contraction of the atmosphere. Additionally,
our multi-wavelength observations allow us to conclude that a haze
component in the atmosphere is required to reproduce the light curves
obtained. This haze scenario has implications for understanding the
photochemistry of Pluto's atmosphere.
---------------------------------------------------------
Title: Preliminary Report on the 14 December 2020 Total Solar
Eclipse Observations
Authors: Pasachoff, Jay M.
2021IAUS..367...43P Altcode:
This paper summarizes preliminary scientific observations from sites
in Chile and Argentina from which the totality was observed on 14
December 2020 at the minimum of the solar-activity/sunspot cycle.
---------------------------------------------------------
Title: History of Astronomy: The Voyager Golden Record in Intellectual
History
Authors: Pasachoff, J.
2021AAS...23722201P Altcode:
In this session cosponsored by the American Astronomical Society's
History of Astronomy Division, we discuss especially the Golden
Record of music, greetings, photographs, and more organized by Jon
Lomberg working for Carl Sagan in spring 1977, shortly before the
Voyagers' launches. Emer Reynolds will discuss the 2019 documentary
— The Farthest — that she directed; we have separately arranged
for those attending the meeting to stream the two-hour theatrical
version. Sarah May will discuss the legacy of the Golden Record in
intellectual history. Nick Oberg will discuss the trajectory of the
Voyager spacecraft in the distant future. Supplementally, as three
nations' missions travel from Earth to Mars this fall, Lomberg will
discuss the disk of greetings and more that was sent to Mars on NASA's
Phoenix lander in 2008.
---------------------------------------------------------
Title: Observations of the December 14, 2020, Total Solar Eclipse
Authors: Pasachoff, J. M.; Rusin, V.; Vansur, R.
2021AAS...23740502P Altcode:
With special arrangements from the Ministry of Science of Chile,
arranged through the U.S. Embassy in Santiago, we were able to have
a group of about a dozen northern-hemisphere astronomers at our site
in Pucón, Chile, near the Villarrica volcano's mid-level ski area,
for the total solar eclipse of December 14, 2020. Though the authors
could not travel there personally, we had a group of a dozen people
there, though that site turned out to be cloudy, and in spite of an
attempt to reach clear areas in Argentina, our group was unable to
cross the border. We collected observations from a few sites from
which the eclipse was visible, as well as space imaging. We worked
to analyze the white-light imaging, making composite images that (a)
were released to compare with predictions of the coronal streamers made
by Predictive Science Inc based on SDO observations of the magnetic
field over the preceding weeks; and (b) comparing the position of the
eclipse comet. Information is available at my eclipse website at <A
href="http://totalsolareclipse.org">http://totalsolareclipse.org</A>
and at the website of the International Astronomical
Union's Working Group on Solar Eclipses at <A
href="http://eclipses.info">http://eclipses.info</A>. JMP's eclipse
research receives major support from grant AGS-1903500 from the Solar
Terrestrial Program, Atmospheric and Geospace Sciences Division,
U.S. National Science Foundation to Williams College.
---------------------------------------------------------
Title: Great Astronomers and their Original Publications
Authors: Pasachoff, J.
2021AAS...23754706P Altcode:
During fall 2020, I taught a hybrid course on Great Astronomers and
their Original Publication, using the first-editions of Copernicus,
Galileo, Kepler, Newton and others from my own collection and the
collection of the Chapin Library of Williams College. The course's
text was the new Cosmos: The Art and Science of the Universe, by
Roberta J. M. Olson and me (Reaktion Books, 2019). My own lectures
and guest lectures from colleagues around the world were via Zoom,
while Williams College's Chapin Librarian Wayne Hammond met small
groups of the 24 enrolled students in a library classroom where the
students in groups of four or five (plus one remote section) viewed and
handled the actual first editions. The course was "writing intensive"
in Williams College's system, so required 3 papers in draft and final
form as well as reports on individual biographies and other books
separately assigned. The course was crosslisted among Astronomy,
History of Science, Leadership Studies, and Science & Technology
Studies departments/programs. Speakers, all via Zoom, included Dan Falk
and Peter Usher (Shakespeare's astronomy), Dava Sobel (Copernicus and
Galileo), Robert Littman (Gutenberg), Michael Mendillo (constellation
maps), Owen Gingerich (Copernicus and volvelles), Mordechai Feingold
(Newton's Principia census), Nick Wilding (Galileo: Sidereus Nuncius
forgery), Meg Ford (Christie's London; 2020 De Revolutionibus auction),
Thomas Lecky (formerly Christie's New York; now Riverrun Books), James
Voelkel '84 (Science History Institute's library, his Kepler biography);
Al Van Helden (Galileo), Hanoch Gutfreund and Jurgen Renn (Einstein),
David DeVorkin (George Ellery Hale; Cecilia Payne-Gaposchkin,
H. N. Russell), and Roberta Olson (related art-history). Wayne Hammond
(Chapin Librarian) discussed Caroline Herschel and others.
---------------------------------------------------------
Title: Anomalies and Fluctuations of Near-surface Air Temperature
at Tianhuangping (Zhejiang), China, Produced by the Longest Total
Solar Eclipse of the 21st Century Under Cloudy Skies
Authors: Peñaloza-Murillo, Marcos A.; Roman, Michael T.; Pasachoff,
Jay M.
2020PASP..132k4503P Altcode: 2019arXiv190503613P
During a total eclipse of the Sun, the solar disk blocked by the
lunar disk produces an instant and strong decline of energy at the
surface. This loss of energy leads to a decreasing air temperatures
near the surface. Anyone under a completely clear sky, with a total
solar eclipse (TSE) in progress, feels a cooling, whose minimum is
reached a few minutes after totality. This drop in temperature is
known as an anomaly and this delay is called thermal lag. During a
TSE air temperature changes appreciably not only in magnitude but
also in timing, depending on weather and geographical conditions. If
the eclipse is partially or totally obscured by clouds, some effects
are produced on the thermal lag. Under clear skies, the temperature
response lags behind the change in solar flux as one expects in TSE;
however, under cloudy skies, the lag can reverse in early and/or late
stages of partial phases. The normal heating of the surface by the
Sun, which drives turbulent motion in the air layer near the surface,
is disrupted during the eclipse. The 2009 TSE in China provided an
opportunity to have a look at these kinds of perturbations caused
by this eclipse. In this paper, the second of a series of three, we
analyze the near-surface air temperature response, at three different
heights over the ground, recorded by the Williams College expedition
under meteorological conditions characterized by cloudy skies during
the longest total solar eclipse of the 21st century on 2009 July 22,
at Tianhuangping (Zhejiang), China. An analysis of the relationship
between solar radiation and air temperature was made by applying a
study previously published in the first paper of this series in which we
evaluated the cloudiness contribution in estimating the impact on global
solar radiation throughout this phenomenon at that site. The analysis of
this response includes linear and absolute negative anomalies as well
as fluctuations, which was undertaken through a statistical study to
get information on the convection activity produced by the latter. The
fluctuations generated by turbulence were studied by analyzing variance
and residuals. The results, indicating a steady decrease and recovery
of both perturbations, were consistent with those published by other
studies for this total solar eclipse.
---------------------------------------------------------
Title: History of Astronomy: The Voyager Golden Record in Intellectual
History
Authors: Pasachoff, J. M.
2020DPS....5240701P Altcode:
In this session cosponsored by the American Astronomical Society's
History of Astronomy Division, we discuss especially the Golden Record
of music, greetings, photographs, and more organized by Jon Lomberg
working for Carl Sagan in spring 1977, shortly before the Voyagers'
launches. Emer Reynolds will discuss the 2019 documentary The Farthest
that she directed; we have separately arranged for those attending
the meeting to stream the two-hour theatrical version. Sarah May will
discuss the legacy of the Golden Record in intellectual history. Nick
Oberg will discuss the trajectory of the Voyager spacecraft in the
distant future. Supplementally, as three nations' missions travel from
Earth to Mars this fall, Lomberg will discuss the disk of greetings
and more that was sent to Mars on NASA's Phoenix lander in 2008.
---------------------------------------------------------
Title: The Galilean Moons I
Authors: Pasachoff, Jay
2020S&T...140c...8P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Compositing Eclipse Images from the Ground and from Space
Authors: Lockwood, Christian A.; Pasachoff, Jay M.; Seaton, Daniel B.;
Sliski, David H.; Lefaudeux, Nicolas
2020RNAAS...4..133L Altcode:
We present composite white-light images of the 2019 July 2, total
solar eclipse, from the minimum of the solar-activity cycle. We exhibit
high-resolution high dynamic range composites from three observation
sites in Chile, including one made of 646 individual ground-based images
and with such a wide field it exceeds the field of view of the Naval
Research Laboratory's C2 and C3 coronagraphs aboard ESA's Solar and
Heliospheric Observatory. We compare the resolution of the coronal
streamers and other magnetic phenomena of the corona. We also show
continuity of features on the solar surface as observed from NOAA's
GOES-16 and GOES-17 Solar Ultraviolet Imager.
---------------------------------------------------------
Title: Total Solar Eclipses Forever
Authors: Pasachoff, J.
2020SPD....5110104P Altcode:
Fifty years ago, Donald Menzel and I had a major expedition to
Miahuatlán, Oaxaca, Mexico (sponsored by National Geographic)
for the March 7, 1970, total solar eclipse, whose path extended up
the US Eastern Seaboard and out to sea at Nantucket. We had a giant
wide-field coronal Littrow spectrograph designed by James G. Baker. We
described the coronal configuration, including a paper in Nature
about the eclipse. I will discuss science from the series of total
solar eclipses since then, including our hopes for observing the 14
December 2020 total solar eclipse whose path of totality will cross
southern Chile and Argentina, as did the 2 July 2019 eclipse. I will
comment on imaging, spectra, and prediction of both configuration
from magnetic field maps and Baily's beads from 3D mapping of the
Moon. Over the decades, 14 of my eclipse expeditions were supported by
the Committee for Research and Exploration of the National Geographic
Society. My recent research on solar eclipses receives major support
from (currently grant AGS-1903500) from the Solar Terrestrial Program,
Atmospheric and Geospace Sciences Division, U.S. National Science
Foundation. Additional student support has recently come from Sigma Xi,
NASA's Massachusetts Space Grant Consortium, and The Global Initiative,
Freeman Foote, and Brandi Funds of Williams College.
---------------------------------------------------------
Title: Compositing Eclipse Images from the Ground and from Space
Authors: Pasachoff, J. M.; Lockwood, C. A.; Seaton, D. B.; Sliski,
D.; Lefaudeux, N.
2020AAS...23611204P Altcode:
We present composite white-light images of the 2 July 2019 total solar
eclipse, from the minimum of the solar-activity cycle. With separate
high-resolution ground-based images, one of them made of 646 individual
images with such a wide field that it exceeds the fields of view of the
Naval Research Laboratory's C2 and C3 coronagraphs aboard ESA's Solar
and Heliospheric Observatory, we have composites based on observations
from the Cerro Tololo Inter-American Observatory and the centerline
of totality at La Higuera in Chile. We compare the resolution of the
coronal streamers and other magnetic phenomena of the corona. We also
show continuity from features on the solar surface as observed from
NASA's Solar Dynamics Observatory and NOAA's GOES-16 Solar Ultraviolet
Imager (SUVI). Acknowledgments: JMP's eclipse research receives major
support from grant AGS-903500 from the Solar Terrestrial Program,
Atmospheric and Geospace Sciences Division, U.S. National Science
Foundation. We had additional student support from the Massachusetts
NASA Space Grant Consortium; Sigma Xi; the Global Initiatives Fund at
Williams College; and the University of Pennsylvania.
---------------------------------------------------------
Title: Size and Shape Constraints of (486958) Arrokoth from Stellar
Occultations
Authors: Buie, Marc W.; Porter, Simon B.; Tamblyn, Peter; Terrell,
Dirk; Parker, Alex Harrison; Baratoux, David; Kaire, Maram; Leiva,
Rodrigo; Verbiscer, Anne J.; Zangari, Amanda M.; Colas, François;
Diop, Baidy Demba; Samaniego, Joseph I.; Wasserman, Lawrence H.;
Benecchi, Susan D.; Caspi, Amir; Gwyn, Stephen; Kavelaars, J. J.;
Ocampo Uría, Adriana C.; Rabassa, Jorge; Skrutskie, M. F.; Soto,
Alejandro; Tanga, Paolo; Young, Eliot F.; Stern, S. Alan; Andersen,
Bridget C.; Arango Pérez, Mauricio E.; Arredondo, Anicia; Artola,
Rodolfo Alfredo; Bâ, Abdoulaye; Ballet, Romuald; Blank, Ted; Bop,
Cheikh Tidiane; Bosh, Amanda S.; Camino López, Matías Aarón;
Carter, Christian M.; Castro-Chacón, J. H.; Caycedo Desprez, Alfonso;
Caycedo Guerra, Nicolás; Conard, Steven J.; Dauvergne, Jean-Luc;
Dean, Bryan; Dean, Michelle; Desmars, Josselin; Dieng, Abdou Lahat;
Bousso Dieng, Mame Diarra; Diouf, Omar; Dorego, Gualbert Séraphin;
Dunham, David W.; Dunham, Joan; Durantini Luca, Hugo A.; Edwards,
Patrick; Erasmus, Nicolas; Faye, Gayane; Faye, Mactar; Ferrario, Lucas
Ezequiel; Ferrell, Chelsea L.; Finley, Tiffany J.; Fraser, Wesley C.;
Friedli, Alison J.; Galvez Serna, Julián; Garcia-Migani, Esteban A.;
Genade, Anja; Getrost, Kai; Gil-Hutton, Ricardo A.; Gimeno, German
N.; Golub, Eli Joseph; González Murillo, Giovanni Francisco; Grusin,
Michael D.; Gurovich, Sebastian; Hanna, William H.; Henn, Santiago M.;
Hinton, P. C.; Hughes, Paul J.; Josephs, John David, Jr.; Joya, Raul;
Kammer, Joshua A.; Keeney, Brian A.; Keller, John M.; Kramer, Emily A.;
Levine, Stephen E.; Lisse, Carey M.; Lovell, Amy J.; Mackie, Jason A.;
Makarchuk, Stanislav; Manzano, Luis E.; Mbaye, Salma Sylla; Mbaye,
Modou; Melia, Raul Roberto; Moreno, Freddy; Moss, Sean K.; Ndaiye,
Diene; Ndiaye, Mapathe; Nelson, Matthew J.; Olkin, Catherine B.;
Olsen, Aart M.; Ospina Moreno, Victor Jonathan; Pasachoff, Jay M.;
Pereyra, Mariana Belen; Person, Michael J.; Pinzón, Giovanni; Pulver,
Eduardo Alejandro; Quintero, Edwin A.; Regester, Jeffrey R.; Resnick,
Aaron Caleb; Reyes-Ruiz, Mauricio; Rolfsmeier, Alex D.; Ruhland,
Trina R.; Salmon, Julien; Santos-Sanz, Pablo; Santucho, Marcos Ariel;
Sepúlveda Niño, Diana Karina; Sickafoose, Amanda A.; Silva, José
S.; Singer, Kelsi N.; Skipper, Joy N.; Slivan, Stephen M.; Smith,
Rose J. C.; Spagnotto, Julio C.; Stephens, Andrew W.; Strabala,
Samuel D.; Tamayo, Francisco J.; Throop, Henry B.; Torres Cañas,
Andrés David; Toure, Labaly; Traore, Alassane; Tsang, Constantine
C. C.; Turner, Jake D.; Vanegas, Santiago; Venable, Roger; Wilson,
John C.; Zuluaga, Carlos A.; Zuluaga, Jorge I.
2020AJ....159..130B Altcode: 2020arXiv200100125B
We present the results from four stellar occultations by (486958)
Arrokoth, the flyby target of the New Horizons extended mission. Three
of the four efforts led to positive detections of the body, and
all constrained the presence of rings and other debris, finding
none. Twenty-five mobile stations were deployed for 2017 June 3 and
augmented by fixed telescopes. There were no positive detections
from this effort. The event on 2017 July 10 was observed by the
Stratospheric Observatory for Infrared Astronomy with one very short
chord. Twenty-four deployed stations on 2017 July 17 resulted in five
chords that clearly showed a complicated shape consistent with a contact
binary with rough dimensions of 20 by 30 km for the overall outline. A
visible albedo of 10% was derived from these data. Twenty-two systems
were deployed for the fourth event on 2018 August 4 and resulted in
two chords. The combination of the occultation data and the flyby
results provides a significant refinement of the rotation period,
now estimated to be 15.9380 ± 0.0005 hr. The occultation data also
provided high-precision astrometric constraints on the position of
the object that were crucial for supporting the navigation for the
New Horizons flyby. This work demonstrates an effective method for
obtaining detailed size and shape information and probing for rings
and dust on distant Kuiper Belt objects as well as being an important
source of positional data that can aid in spacecraft navigation that
is particularly useful for small and distant bodies.
---------------------------------------------------------
Title: Eclipse Tests of General Relativity in the 21st Century
Authors: Pasachoff, J. M.
2020AAS...23500101P Altcode:
The analysis of the results, and their reception over the years, of the
1919 total solar eclipse observations from Principe by Arthur Eddington
and colleague Edwin Cottingham, and from Sobral (Brazil) by Andrew
Crommelin and Charles Davidson, all in collaboration with Astronomer
Royal Sir Frank Watson Dyson, will be discussed by experts Daniel
Kennefick (US) and Jeffrey Crelinsten (Canada). At this Centennial,
I will discuss current repetitions of this "Eddington Experiment"
and future plans. <P />JMP's eclipse research receives major support
from grant AGS-903500 from the Solar Terrestrial Program, Atmospheric
and Geospace Sciences Division, U.S. National Science Foundation.
---------------------------------------------------------
Title: Early Results from the Solar-Minimum 2019 Total Solar Eclipse
Authors: Pasachoff, J. M.; Lockwood, C. A.; Inoue, J. L.; Meadors,
E. N.; Voulgaris, A.; Sliski, D.; Sliski, A.; Reardon, K. P.; Seaton,
D. B.; Caplan, R. M.; Downs, C.; Linker, J. A.; Sterling, A. C.
2020AAS...23535903P Altcode:
We report on first results from our observations in Chile on July
2, 2019, that revealed the extreme-solar-minimum corona, with only
equatorial streamers and with visible polar plumes. We have observations
in clear skies from our three observing sites: (1) The Cerro Tololo
Inter-American Observatory, 7,240-foot altitude, 2 min 6 sec; (2)
La Higuera, centerline, 2,500-foot altitude, 2 min 35 sec totality;
(3) La Serena, sea level, 2 min 15 sec totality. Prominences on the
limb provided orientation and coordination with spacecraft observations
from NOAA's GOES-R Solar Ultraviolet Imager (SUVI) and the Atmospheric
Imaging Assembly (AIA) on NASA's Solar Dynamics Observatory (SDO). The
double-diamond ring at second contact will extend our determination of
a new IAU-recommended value of the solar diameter through comparison
with models taking into account the precise lunar profile. Our coronal
spectra from slitless spectrographs, from CTIO, showed the Fe XIV 530.3
nm green line substantially weaker than the Fe X 637.4 nm red line,
corresponding to the relatively low coronal temperature at this phase
of the solar-activity cycle. On the spectra we also detected the weak
coronal emission line of Ar X at 553.3 nm, as we also detected at
the previous total solar eclipse of August 21, 2017, in the USA. We
show a comparison of the eclipse observation with a prediction of the
structure of the corona from an MHD model, carried out by Predictive
Science Inc. (PSI). We consider the lines of sight to NASA's Parker
Solar Probe at the times of total eclipses, when we can examine the
coronal imaging in terms of electron density to compare with the in
situ measurements. <P />We received major support from grant AGS-903500
from the Solar Terrestrial Program, Atmospheric and Geospace Sciences
Division, U.S. National Science Foundation. The CTIO site was courtesy
of Associated Universities for Research in Astronomy (AURA). We had
additional student support from the Massachusetts NASA Space Grant
Consortium; Sigma Xi; the Global Initiatives Fund at Williams College;
and the University of Pennsylvania. PSI was supported by AFOSR, NASA,
and NSF. ACS received support from the NASA/HGI program, and from
the MSFC Hinode project. AV thanks the mathematician Christophoros
Mouratidis for his help with the data reduction of the spectra.
---------------------------------------------------------
Title: Early results from the solar-minimum 2019 total solar eclipse
Authors: Pasachoff, Jay M.; Lockwood, Christian A.; Inoue, John L.;
Meadors, Erin N.; Voulgaris, Aristeidis; Sliski, David; Sliski, Alan;
Reardon, Kevin P.; Seaton, Daniel B.; Caplan, Ronald M.; Downs, Cooper;
Linker, Jon A.; Schneider, Glenn; Rojo, Patricio; Sterling, Alphonse C.
2020IAUS..354....3P Altcode:
We observed the 2 July 2019 total solar eclipse with a variety of
imaging and spectroscopic instruments recording from three sites
in mainland Chile: on the centerline at La Higuera, from the Cerro
Tololo Inter-American Observatory, and from La Serena, as well
as from a chartered flight at peak totality in mid-Pacific. Our
spectroscopy monitored Fe X, Fe XIV, and Ar X lines, and we imaged Ar
X with a Lyot filter adjusted from its original H-alpha bandpass. Our
composite imaging has been compared with predictions based on modeling
using magnetic-field measurements from the pre-eclipse month. Our
time-differenced sites will be used to measure motions in coronal
streamers.
---------------------------------------------------------
Title: Demonstrating the Cosmic Distance Ladder with Cepheids
Authors: Pasachoff, Jay M.; Mativi, Jason W.
2020PhTea..58....6P Altcode:
To span the great distance from our solar system to the farthest
clusters of galaxies in our universe, astronomers break down the
distance indicators into steps. The nearest ones are measured
geometrically, with what is known as parallax. Among the objects
whose distances are thus directly measured are a rare type of star
known as a Cepheid variable. Henrietta Leavitt about a hundred
years ago discovered, by looking at a number of such stars in the
Small Magellanic Cloud, that the brighter the star, the longer its
period. This secondary indicator can be used in nearby galaxies to
calibrate as a standard candle a specific type of supernova (Type Ia,
from explosions of white-dwarf stars), whose peak intensities are so
bright that they can be seen throughout the observable universe.
---------------------------------------------------------
Title: Measuring the Scale of the Solar System through Transits
of Mercury
Authors: Pasachoff, Jay; Backhaus, Udo; Knülle-Wenzel, Alfred;
Zender, Joe J.
2019EPSC...13...62P Altcode:
We discuss use of past transits of Venus and Mercury for finding
the distance from the Earth to the Sun, and propose a student and
citizen-science exercise to make that measurement through simultaneous
observations of the 11 November 2019 transit of Mercury from widely
separated terrestrial sites.
---------------------------------------------------------
Title: The 1919 Eclipse Expedition Results in the Context of the
2019 Age of LIGO
Authors: Pasachoff, Jay; Kennefick, Julia
2019EPSC...13.1951P Altcode:
To mark the centennial of the 29 May 1919 total solar eclipse observed
from Principe and Brazil from which Eddington, Dyson, Crommelin and
others took and/or analyzed data about the deflection of starlight
near the Sun, endorsing Albert Einstein's prediction from his General
Theory of Relativity, our session includes authors of recent books
analyzing the 1919 events and subsequent discussions. Our session also
includes astronomers who are working to mark and establish a lasting
educational presence at Roça Sundy, Principe.
---------------------------------------------------------
Title: Transits of Mercury and General Relativity from observations,
and the 2019 November 11 transit
Authors: Sigismondi, Costantino; Bordoni, Luigi; Pasachoff, Jay
2019EPSC...13..993S Altcode:
The transit of Mercury of November 11, 2019 provides the opportunity
to test a method of measuring the solar diameter and shape (due
to the oblateness) better than 0.1", or 70 Km of resolution on the
Sun. Beyond the General Relativity implications of Mercury itself, we
exploit the most precise ephemerides to achieve 0.1" with ground-based
instruments of the solar diameter, of which monitoring the secular
variations (related to our climate), as well as transient variations
as potential proxies of major flares and Coronal Mass Ejections (to
predict space weather).
---------------------------------------------------------
Title: Depictions of the Moon in Western Visual Culture
Authors: Pasachoff, J. M.; Olson, Roberta J. M.
2019oeps.book...55P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Education and Outreach About Science at the 2017 Eclipse
Authors: Pasachoff, J. M.
2019ASPC..516..331P Altcode:
When a solar eclipse is visible from a country, especially a total solar
eclipse, we astronomers have the attention of the general public in
addition to that of scientists and students. At the time of the 2017
solar eclipse whose totality crossed the Continental United States,
with a partial eclipse visible from all states, we were able to provide
students and the general public, as well as scientists a wide range of
substantial scientific information about eclipses, about the Sun, and
about the rest of the Universe. For the Working Group on Solar Eclipses
of the International Astronomical Union, we also acted as a liaison
providing letters of invitation that were useful for foreign colleagues
obtaining U.S. visas and helping to arrange observing locations.
---------------------------------------------------------
Title: Eclipse Megamovie 2017 Successes and Potential For Future Work
Authors: Peticolas, L.; Hudson, H.; Johnson, C.; Zevin, D.; White,
V.; Oliveros, J. C. M.; Ruderman, I.; Koh, J.; Konerding, D.; Bender,
M.; Cable, C.; Kruse, B.; Yan, D.; Krista, L.; Collier, B.; Fraknoi,
A.; Pasachoff, J. M.; Filippenko, A. V.; Mendez, B.; McIntosh, S. W.;
Filippenko, N. L.
2019ASPC..516..337P Altcode:
In 2011, an "Eclipse Megamovie" was envisioned for the 2017 total
solar eclipse that would be created using the public's photographs of
the Sun's corona as frames in a movie illuminating dynamic changes in
the chromosphere and corona. On August 21, 2017, our team collected
photographs of the total solar eclipse from thousands of volunteers
with telescopes, DSLR (Digital Single-Lens Reflex) cameras, and mobile
device cameras setup across the path of totality. Our efforts resulted
in 1,190 photographers contributing 50,016 DSLR photographs in a final
open-source, public archive that is 766 GB in size. All photographs
in this archive are Creative Commons zero (CC0), making them freely
available for public use. From mobile devices, we obtained an archive
of 60,000 images, 211 GB in size. The first Eclipse Megamovie video
was compiled and made available to the public a few hours after the
Moon's shadow left the U.S. East Coast. For two weeks, additional
images were added to this video, as volunteers uploaded them to the
project server. The project also resulted in a comprehensive website
with 12,749 users sufficiently interested in the project to each create
a user profile on the website, several short documentaries, 190 articles
and press releases, open-source code for use in future related efforts,
and hundreds of public presentations across the country prior to the
eclipse. Information on how to access these resources is included in
this paper.
---------------------------------------------------------
Title: Transit of Mercury and General Relativity from Observations,
and the 2019 November 11 Transit
Authors: Sigismondi, C.; Bordoni, L.; Pasachoff, J.
2019JOA.....9c...8S Altcode:
The transit of Mercury of November 11 2019, provides the opportunity
to test a method of measuring the solar diameter and shape (due
to the oblateness) better than 0.1", or 70 km of resolution on the
Sun. Beyond the General Relativity implications of Mercury itself, we
exploit the most precise ephemerides to achieve 0.1" with ground-based
instruments of the solar diameter, of which monitoring the secular
variations (related to our climate), as well as transient variations
as potential proxies of major flares and Coronal Mass Ejections (to
predict space weather).
---------------------------------------------------------
Title: Solar Seeing
Authors: Pasachoff, Jay M.
2019S&T...137f...8P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The IAU and Solar Eclipses
Authors: Pasachoff, Jay M.; Hiei, Eijiro; Perez, Cielo
2019IAUS..349..459P Altcode:
We describe the history of solar-eclipse supervision since the formation
of the International Astronomical Union, as the supervising body morphed
from a full commission to a subcommission to its current status as an
Inter-Divisional Working Group of the Education, Outreach and Heritage
Division and the Sun and Heliosphere Division.
---------------------------------------------------------
Title: Book Review: The Sun
Authors: Golub, Leon; Pasachoff, Jay M.
2018JAHH...21..241C Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Images and Spectra of the 2017 Total Solar Eclipse Corona
From Our Oregon Site
Authors: Pasachoff, Jay M.; Lockwood, Christian; Meadors, Erin; Yu,
Ross; Perez, Cielo; Peñaloza-Murillo, Marcos A.; Seaton, Daniel B.;
Voulgaris, Aris; Dantowitz, Ron; Rušin, Vojtech; Economou, Thanasis
2018FrASS...5...37P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Airborne and Ground Observations of the Stellar Occultation
by Triton on 5 October 2017
Authors: Person, Michael J.; Schindler, Karsten; Bosh, Amanda S.; Wolf,
Juergen; Levine, Stephen E.; Zuluaga, Carlos A.; Pfueller, Enrico;
Caton, Daniel; Patton, Alexander; Pasachoff, Jay; Oswalt, Terry;
von Hippel, Ted; Brothers, Timothy; Operations Tea, Sofia; Lincoln
Labs Firepond Observations Team; Triton Occultation Observation Team
2018DPS....5041610P Altcode:
On 5 October 2017, Triton occulted the 13<SUP>th </SUP>magnitude star
UCAC4 410-143659 as seen from the Eastern US, North Atlantic, and
Europe. Our collaboration observed this event from the Stratospheric
Observatory for Infrared Astronomy (SOFIA) aircraft, as well as numerous
(over two dozen) ground stations throughout the US and Europe. Here, we
present the preliminary results of analyzing this dataset and highlight
a number of features of Triton's atmosphere. Initial reduction of the
data indicates that the atmospheric pressure increases seen throughout
the 90's have stabilized or perhaps begun to reverse, as the current
pressures are more comparable to those measured during the earlier
occultations of the 1990's than the later ones, although still greater
than the pressure observed by Voyager 2 in 1989. Careful calibration
of the multi-wavelength observations made from SOFIA indicates a clear
atmosphere at the levels to which we are sensitive (>35 km), with no
signs of the various particulate dust plumes or cloud-like structures
seen by Voyager 2 below 8 km altitude. Data reduction is progressing
and a final report is in preparation.
---------------------------------------------------------
Title: Who named the largest moons of Jupiter? Johannes Kepler
contributed
Authors: Pasachoff, Jay M.
2018iau3.book...38P Altcode:
It is little known that one day after Galileo discovered what are
generally called the Galilean moons of Jupiter (which is very well
visible in the evening sky this month), Simon Marius of Nuremberg
independently discovered them, if we go by written notes. (If we go
by verbal accounts, Marius may well have seen them first.) In his
book Mundus Iovialis (1614) Marius credits Kepler for giving him the
idea to name the moons Io, Europa, Ganymede, and Callisto, the names
that have stuck, even if the set of moons are known as the Galilean
moons. Galileo took strong objection to Marius's report of independent
discovery but historical verification favors Marius's claim. <P />At the
Smithsonian Institution's National Air and Space Museum, two audio clips
(#3 and #48) about Kepler's work (51 seconds and 2 minutes 41 seconds,
respectively) recorded by Pasachoff are available to visitors; they are
available also at https://airandspace.si.edu/explore-universe-audio-tour
---------------------------------------------------------
Title: Science at the Great American Eclipse
Authors: Pasachoff, Jay M.
2018A&G....59d4.19P Altcode:
Jay Pasachoff rounds up observations made by citizen scientists,
individuals, groups and an array of spacecraft.
---------------------------------------------------------
Title: Das Beispiel Hilmar und Waltraut - Ehepaare am Himmel der
Kleinen Planeten
Authors: Schmadel, Lutz D.; Pasachoff, Jay M.; Ting, Peter M.
2018AcHA...64..281S Altcode:
The names of the minor planets are not just arabesques of its
discoverers, but they also reflect the ever-changing zeitgeist of more
than two centuries. Increasingly, the list of names is no longer to be
regarded as merely an inventory of deceased astronomers or a list of
mythological figures. More and more not only prominent figures in the
history of astronomy but also their spouses have given their names to
minor planets. In grateful memory of our colleagues Hilmar Duerbeck and
Waltraut Seitter, we introduce a new catalog listing pairs (or triples)
of married couples after whom minor planets have been named.
---------------------------------------------------------
Title: Predicting the corona for the 21 August 2017 total solar
eclipse
Authors: Mikić; , Zoran; Downs, Cooper; Linker, Jon A.; Caplan, Ronald
M.; Mackay, Duncan H.; Upton, Lisa A.; Riley, Pete; Lionello, Roberto;
Török, Tibor; Titov, Viacheslav S.; Wijaya, Janvier; Druckmüller,
Miloslav; Pasachoff, Jay M.; Carlos, Wendy
2018NatAs...2..913M Altcode: 2018NatAs.tmp..120M
The total solar eclipse that occurred on 21 August 2017 across the
United States provided an opportunity to test a magnetohydrodynamic
model of the solar corona driven by measured magnetic fields. We used
a new heating model based on the dissipation of Alfvén waves, and
a new energization mechanism to twist the magnetic field in filament
channels. We predicted what the corona would look like one week before
the eclipse. Here, we describe how this prediction was accomplished,
and show that it compared favourably with observations of the
eclipse in white light and extreme ultraviolet. The model allows us to
understand the relationship of observed features, including streamers,
coronal holes, prominences, polar plumes and thin rays, to the magnetic
field. We show that the discrepancies between the model and observations
arise from limitations in our ability to observe the Sun's magnetic
field. Predictions of this kind provide opportunities to improve the
models, forging the path to improved space weather prediction.
---------------------------------------------------------
Title: Configuration of and Motions in the Solar Corona at the 2017
Total Solar Eclipse
Authors: Pasachoff, Jay M.; Rusin, Vojtech; Vanur, Roman; Economou,
Thanasis; Voulgaris, Aristeidis; Seiradakis, John H.; Seaton,
Daniel; Dantowitz, Ronald; Lockwood, Christian A.; Nagle-McNaughton,
Timothy; Perez, Cielo; Meadors, Erin N.; Marti, Connor J.; Yu, Ross;
Rosseau, Brendan; Ide, Charles A.; Daly, Declan M.; Davis, Allen
Bradford; Lu, Muzhou; Steele, Amy; Lee, Duane; Freeman, Marcus J.;
Sliski, David; Rousseva, Ana; Greek Salem (Oregon) Team; Voulgaris,
Aristeidis; Seiradakis, John Hugh; Koukioglou, Stavros; Kyriakou,
Nikos; Vasileiadou, Anna; Greek Carbondale (Illinois) Team; Economou,
Thanasis; Kanouras, Spyros; Irakleous, Christina; Golemis, Adrianos;
Tsioumpanika, Nikoleta; Plexidas, Nikos; Tzimkas, Nikos; Kokkinidou,
Ourania
2018AAS...23232510P Altcode:
We report on high-contrast data reduction of white-light images from
the August 21, 2017, total solar eclipse. We show the configuration of
the solar corona at this declining phase of the solar-activity cycle,
with the projection onto the plane of the sky of the three-dimensional
coronal streamers plus extensive polar plumes. We discuss the
relation of the white-light coronal loops visible in our observations
with extreme-ultraviolet observations from NASA’s Solar Dynamics
Observatory Atmospheric Imaging Assembly (AIA) and NOAA’s GOES-16
Solar Ultraviolet Imager (SUVI). We show differences and motions
over a 65-minute interval between observations from our main site
at Willamette University in Salem, Oregon, and a subsidiary site in
Carbondale, Illinois. We discuss, in particular, a giant demarcation
about 1 solar radius outward in the southwest that crosses the
radial streamers.Our observations of the eclipse were sponsored
in large part by the Committee for Research and Exploration of the
National Geographic Society and by the Solar Terrestrial Program of
the National Geographic Society. Additional support was received
from the NASA Massachusetts Space Grant Consortium, the Sigma Xi
honorary scientific society, the University of Pennsylvania (for
DS), the Slovak Academy of Sciences VEGA project 2/0003/16, and the
Freeman Foote Expeditionary and Brandi funds at Williams College. We
thank Stephen Thorsett, Rick Watkins, and Honey Wilson of Willamette
University for their hospitality. See http://totalsolareclipse.org
or http://sites.williams.edu/eclipse/2017-usa/.
---------------------------------------------------------
Title: Simon Marius's Mundus Iovialis and the Discovery of the Moons
of Jupiter
Authors: Pasachoff, Jay M.
2018smhr.book..191P Altcode:
Though the details of who was first to see the four major satellites
of Jupiter are obscured by the mists of time, it seems that Simon Mayr
(Marius) nearly simultaneously and independently discovered them and
noted the discovery only 1 day after Galileo similarly discovered and
noted it. The twin discoveries were confused by the use of different
calendars by Marius and by Galileo, the former using the Julian calendar
then still in use in Protestant regions and the latter using the new
Gregorian calendar that was adopted in Catholic regions. Galileo was
particularly sensitive to his priority, and the use of 1609 by Marius
in the title of his Mundus Iovialis of 1614 raised particular ire,
though adding the required 10 days for the conversion from O.S. to
N.S. brought Marius's discovery into early 1610. In the long run,
we now use the names that Marius gave—Io, Europa, Ganymede, and
Callisto—to what are called the Galilean satellites.
---------------------------------------------------------
Title: Preparing a Nation for the Eclipse of a Generation -
Authors: Speck, Angela; Habbal, Shadia; Tresch Fienberg, Richard;
Kentrianakis, Michael; Fraknoi, Andrew; Nordgren, Tyler; Penn,
Matthew; Pasachoff, Jay M.; Bakich, Michael; Winter, Henry; Gay,
Pamela; Motta, Mario
2018AAS...23122002S Altcode:
On August 21st 2017, there was a total solar eclipse visible from
a vast swath of the US.In preparation for that event, the American
Astronomical society created a taskforce charged with planning
for the eclipse for the entire nation. The preparations included
interfacing with the public, the media, non-profit organizations and
governmental organizations. Preliminary data suggests that nearly 90%
of American adults watched the eclipse either directly or via live
streams. Moreover, there were no major problems associated with the
event, in spite of valiant attempts from, e.g. imprope solar viewing
materials. The eclipse offered opportunities for many scientific
experiments within and ebyond astronomy. Here we present on the work
of the taskforce, and the lessons learned as well as lesser known
science experiments undertaken during the eclipse.
---------------------------------------------------------
Title: Early Science Results from the Williams College Eclipse
Expedition
Authors: Pasachoff, Jay M.; Person, Michael J.; Dantowitz, Ron;
Lockwood, Christian A.; Nagle-McNaughton, Tim; Meadors, Erin N.;
Perez, Cielo C.; Marti, Connor J.; Yu, Ross; Rosseau, Brendan; Daly,
Declan M.; Ide, Charles A.; Davis, Allen B.; Lu, Muzhou; Sliski, David;
Seiradakis, John; Voulgaris, Aris; Rusin, Vojtech; Peñaloza-Murillo,
Marcos A.; Roman, Michael; Seaton, Daniel B.; Steele, Amy; Lee,
Duane M.; Freeman, Marcus J.
2018AAS...23122006P Altcode:
We describe our first cut of data reduction on a wide variety of
observations of the solar corona and of the effect of the penumbra
and umbra on the terrestrial atmosphere, carried out from our eclipse
site on the campus of Willamette University in Salem, Oregon. Our
team of faculty, undergraduate students, graduate students, and other
colleagues observed the eclipse, taking images and spectra with a
variety of sensors and telescopes. Equipment included frame-transfer
cameras observing at 3 Hz in 0.3 nm filters at the coronal green and red
lines to measure the power spectrum of oscillations in coronal loops or
elsewhere in the lower corona; 3 spectrographs; a variety of telescopes
and telephotos for white-light imaging; a double Lyot system tuned at
Fe XIV 530.3 nm (FWHM 0.4 nm) and Fe X 637.4 nm (FWHM 0.5 nm); and a
weather station to record changes in the terrestrial atmosphere. We
are comparing our observations with predictions based on the previous
mapping of the photospheric magnetic field, and preparing wide-field
complete coronal imaging incorporating NOAA/NASA GOES-16 SUVI and
NRL/NASA/LASCO for the corona outside our own images (which extend,
given the completely clear skies we had, at least 4 solar radii),
and NASA SDO/AIA and NOAA/NASA GOES-16 SUVI for the solar disk. One
of our early composites appeared as Astronomy Picture of the Day for
September 27: https://apod.nasa.gov/apod/ap170927.htmlOur expedition
was supported in large part by grants from the Committee for Research
and Exploration of the National Geographic Society and from the Solar
Terrestrial Program of the Atmospheric and Geospace Sciences Division of
the National Science Foundation, with additional student support from
the STP/AGS of NSF, the NASA Massachusetts Space Grant Consortium, the
Sigma Xi honorary scientific society, the Clare Booth Luce Foundation
studentship and the Freeman Foote Expeditionary Fund at Williams
College, other Williams College funds, and U. Pennsylvania funds.
---------------------------------------------------------
Title: First 2017-total-eclipse results from the Williams College team
Authors: Pasachoff, J.; Dantowitz, R.; Rusin, V.; Seiradakis, J. H.;
Voulgaris, A.; Seaton, D. B.; Davis, A. B.; Lu, M.; Sliski, D.; Ladd,
E. F.; Economou, T.; Peñaloza-Murillo, M. A.; Nagle-McNaughton, T.
2017AGUFMSH13B2476P Altcode:
We report on a wide range of observations we carried out during the
total solar eclipse of August 21, 2017. Our main site was on the campus
of Willamette University, Salem, Oregon, at which we had a variety of
telescopes, spectrographs, cameras, a grism, and terrestrial-atmospheric
measuring devices. Our goals included differentiating between models
of coronal heating through measuring power-spectra of coronal loops
in the [Fe XIV] and [Fe X] emission lines at multi-Hertz cadence
with a frame-transfer CCD and otherwise; following coronal structure
over the solar-activity cycle; comparing the results of a full-MHD
prediction with actual coronal streamers; studying the dynamics of
coronal plumes given the minimum phase of the solar-activity cycle;
measuring the variation of the corona over the solar-activity cycle from
our continuing measurements of the green-line/red-line intensity ratio;
studying a variety of additional coronal emisson lines; high-resolution
coronal imaging compared with overlapping images from space coronagraphs
aboard SoHO and STEREO; comparing with AIA/SDO, HMO/SDO, SUVI/GOES-16,
and SWAP/PROBA2 space images; and more. Our research has been
supported in large part by grants from the Committee for Research
and Exploration of the National Geographic Society and from the Solar
Terrestrial Program of the Atmospheric and Geospace Sciences Division
of the National Science Foundation, with additional support from Sigma
Xi. Additional support for undergraduate participation came from the
NSF, the NASA Massachusetts Space Grant Consortium, and the Clare Booth
Luce Foundation, with travel support from the Freeman Foote Fund, the
Rob Spring Fund, the Brandi Fund, and other sources at Williams College.
---------------------------------------------------------
Title: Pluto occultation on 2015 June 29 UTC with central flash and
atmospheric spikes just before the New Horizons flyby
Authors: Pasachoff, Jay M.; Babcock, Bryce A.; Durst, Rebecca F.;
Seeger, Christina H.; Levine, Stephen E.; Bosh, Amanda S.; Person,
Michael J.; Sickafoose, Amanda A.; Zuluaga, Carlos A.; Kosiarek,
Molly R.; Abe, Fumio; Nagakane, Masayuki; Suzuki, Daisuke; Tristram,
Paul J.; Arredondo, Anicia
2017Icar..296..305P Altcode:
We observed the occultation by Pluto of a 12th magnitude star, one of
the two brightest occultation stars ever in our dozen years of continual
monitoring of Pluto's atmosphere through such studies, on 2015 June
29 UTC. At the Univ. of Canterbury Mt. John Observatory (New Zealand),
under clear skies throughout, we used a POETS frame-transfer CCD at 10
Hz with GPS timing on the 1-m McLellan telescope as well as an infrared
camera on an 0.6-m telescope and three-color photometry at a slower
cadence on a second 0.6-m telescope. At the Auckland Observatory, we
used a POETS and a PICO on 0.5-m and 0.4-m telescopes, with 0.4 s and 2
s cadences, respectively, obtaining ingress observations before clouds
moved in. The Mt. John light curves show a central flash, indicating
that we were close to the center of the occultation path. Analysis
of our light curves show that Pluto's atmosphere remains robust. The
presence of spikes at both sites in the egress and ingress shows
atmospheric layering. We coordinated our observations with aircraft
observations (Bosh et al., 2017) with the Stratospheric Observatory for
Infrared Astronomy (SOFIA). Our chords helped constrain the path across
Pluto that SOFIA saw. Our ground-based and airborne stellar-occultation
effort came only just over two weeks of Earth days and two Pluto days
before the flyby of NASA's New Horizons spacecraft.
---------------------------------------------------------
Title: Solar-system Education for the 2017 Total Solar Eclipse
Authors: Pasachoff, Jay M.
2017DPS....4910103P Altcode:
I describe an extensive outreach program about the Sun, the silhouette
of the Moon, and the circumstances both celestial and terrestrial
of the August 21, 2017, total solar eclipse. Publications included
a summary of the last decade of solar-eclipse research for Nature
Astronomy, a Resource Letter on Observing Solar Eclipses for the
American Journal of Physics, and book reviews for Nature and for Phi
Beta Kappa's Key Reporter. Symposia arranged include sessions at AAS,
APS, AGU, and AAAS. Lectures include all ages from pre-school through
elementary school to high school to senior-citizen residences. The
work, including the scientific research about the solar corona that
is not part of this abstract, was supported by grants from the Solar
Terrestrial Program of the Atmospheric and Geospace Sciences Division
of NSF and from the Committee for Research and Exploration of the
National Geographic Society. Additional student support was received
from NSF, NASA's Massachusetts Space Grant Consortium, the Honorary
Research Society Sigma Xi, the Clare Booth Luce Foundation, and funds
at Williams College.
---------------------------------------------------------
Title: Syzygy Information: Lunar Limb Profiles at Total Eclipses of
the Decade
Authors: Pasachoff, Jay M.; Jubier, Xavier; Wright, Ernest
2017DPS....4941717P Altcode:
The topographic 3D mapping of the lunar surface by the Japanese Kaguya
and NASA's Lunar Reconnaissance Orbiter has led to greatly improved
predictions of Baily's beads at total solar eclipses. This information
has been included in the program Solar Eclipse Maestro. Matching the
predictions with observations of Baily's beads made at total solar
eclipses, including the 21 August 2017 eclipse as well as previous
total and annular eclipses, may even improve the accuracy of the solar
diameter used as a standard by the International Astronomical Union.
---------------------------------------------------------
Title: The 2016 Transit of Mercury and the Solar Parallax
Authors: Pasachoff, Jay M.; Backhaus, Udo; Gährken, Bernd; Schneider,
Glenn
2017DPS....4920004P Altcode:
We observed the 9 May 2016 transit of Mercury with the 1.6-m New Solar
Telescope of the Big Bear Solar Observatory of the New Jersey Institute
of Technology in California and with smaller telescopes in Germany. The
solar granulation behind the silhouette of Mercury can be aligned,
showing Mercury's parallax. From these observations, the value of the
solar parallax can be determined, showing historical parallels. As a
second method of making the parallactic shift of Mercury visible and the
distance to the sun measurable, we aligned photos taken with telescopes
of shorter focal lengths, for instance, by using the prominent sunspots.
---------------------------------------------------------
Title: Heliophysics at total solar eclipses
Authors: Pasachoff, Jay M.
2017NatAs...1E.190P Altcode:
Observations during total solar eclipses have revealed many secrets
about the solar corona, from its discovery in the 17th century to
the measurement of its million-kelvin temperature in the 19th and
20th centuries, to details about its dynamics and its role in the
solar-activity cycle in the 21st century. Today's heliophysicists
benefit from continued instrumental and theoretical advances, but
a solar eclipse still provides a unique occasion to study coronal
science. In fact, the region of the corona best observed from the
ground at total solar eclipses is not available for view from any
space coronagraphs. In addition, eclipse views boast of much higher
quality than those obtained with ground-based coronagraphs. On 21
August 2017, the first total solar eclipse visible solely from what
is now United States territory since long before George Washington's
presidency will occur. This event, which will cross coast-to-coast
for the first time in 99 years, will provide an opportunity not only
for massive expeditions with state-of-the-art ground-based equipment,
but also for observations from aloft in aeroplanes and balloons. This
set of eclipse observations will again complement space observations,
this time near the minimum of the solar activity cycle. This review
explores the past decade of solar eclipse studies, including advances in
our understanding of the corona and its coronal mass ejections as well
as terrestrial effects. We also discuss some additional bonus effects
of eclipse observations, such as recreating the original verification
of the general theory of relativity.
---------------------------------------------------------
Title: First Results from the August 21, 2017, Total Solar Eclipse
Authors: Pasachoff, Jay M.
2017SPD....4820803P Altcode:
I report on the observations planned and, weather permitting, made
from our site in Salem, Oregon, at the August 21, 2017, total solar
eclipse. I also give a first report on collaborators' successes,
including Megamovie and simultaneous space observations. We also
describe our participation in PBS's NOVA on the eclipse that was to be
aired on public television on eclipse night. Our eclipse expedition is
supported in large part by grants from the Solar Terrestrial Program
of the Atmospheric Sciences Division of NSF and by the Committee for
Research and Exploration of the National Geographic Society.
---------------------------------------------------------
Title: Results from and Plans for the Two 2017 Solar Eclipses
Authors: Pasachoff, Jay M.; Seaton, Daniel; Kentrianakis, Michael;
Fischer, Daniel
2017AAS...23030106P Altcode:
At this writing fresh from observing the 26 February 2017 annular solar
eclipse in exceptionally clear sky from sites in Patagonia, Argentina,
we show images from the centerline near Facundo showing Baily's beads
and central annularity of the magnitude 99.3% eclipse. From close to the
edge of the path from sites north of Facundo within the northern limit
(images by Daniel Fischer) and north of Sarmiento at the southern limit
(images by Jörg Schoppmeyer), we show unfiltered images that show
substantial solar chromosphere with innermost corona above it. We
also show SWAP and SDO eclipse images.For the 21 August 2017 total
solar eclipse, we describe our plans for observing coronal structure
above the limb from the ground in Oregon and for ultraviolet imaging
on the solar disk at the time of the terrestrial eclipse through six
filters using the new Solar Ultraviolet Imager (SUVI) on the National
Oceanic and Atmospheric Administration's GOES-16 spacecraft, planned
along with three similar spacecraft for coronal coverage for the next
two decades. SUVI has the biggest overlapping field of view, 53 arcmin
square, of any multi-channel space-based EUV imager.Our research on
the 2017 total solar eclipse is supported by grants from the Committee
for Research and Exploration of the National Geographic Society and
from the Solar Terrestrial Program of the Atmospheric and Geospace
Sciences Division of the National Science Foundation. NOAA NCEI are
the acronyms for the National Oceanic and Atmospheric Administration's
National Centers for Environmental Information.
---------------------------------------------------------
Title: Books and Other Resources for Education about the August 21,
2017, Solar Eclipse
Authors: Pasachoff, Jay M.; Fraknoi, Andrew; Kentrianakis, Michael
2017AAS...23010804P Altcode:
As part of our work to reach and educate the 300+ million Americans
of all ages about observing the August 21 solar eclipse, especially
by being outdoors in the path of totality but also for those who will
see only partial phases, we have compiled annotated lists of books,
pamphlets, travel guides, websites, and other information useful for
teachers, students, and the general public and made them available
on the web, at conferences, and through webinars. Our list includes
new eclipse books by David Barron, Anthony Aveni, Frank Close, Tyler
Nordgren, John Dvorak, Michael Bakich, and others. We list websites
accessible to the general public including those of the International
Astronomical Union Working Group on Eclipses (http://eclipses.info,
which has links to all the sites listed below); the AAS Eclipse
2017 Task Force (http://eclipse2017.aas.org); NASA Heliophysics
(http://eclipse.nasa.gov); Fred Espenak (the updated successor
to his authoritative "NASA website": http://EclipseWise.com);
Michael Zeiler (http://GreatAmericanEclipse.com); Xavier Jubier
(http://xjubier.free.fr/en/site_pages/solar_eclipses/);
Jay Anderson (meteorology: http://eclipsophile.com);
NASA's Eyes (http://eyes.nasa.gov/eyes-on-eclipse.html
and its related app); the Astronomical Society of
the Pacific (http://www.astrosociety.org/eclipse);
Dan McGlaun (http://eclipse2017.org/); Bill
Kramer (http://eclipse-chasers.com). Specialized
guides include Dennis Schatz and Andrew Fraknoi's
Solar Science for teachers (from the National Science Teachers
Association:http://www.nsta.org/publications/press/extras/files/solarscience/SolarScienceInsert.pdf),
and a printing with expanded eclipse coverage of Jay Pasachoff's,
Peterson Field Guide to the Stars and Planets (14th printing of the
fourth edition, 2016: http://solarcorona.com).A version of our joint
list is to be published in the July issue of the American Journal
of Physics as a Resource Letter on Eclipses, adding to JMP's 2010,
"Resource Letter SP-1 on Solar Physics," AJP, 78, September, 890-901.
---------------------------------------------------------
Title: Astronomy: An all-American eclipse
Authors: Pasachoff, Jay
2017Natur.545..409P Altcode:
Jay Pasachoff enjoys four books heralding this summer's US total
solar eclipse.
---------------------------------------------------------
Title: Educating the Public about the 2017 Total Solar Eclipse
Authors: Pasachoff, Jay M.
2017AAS...22941103P Altcode:
On behalf of the International Astronomical Union's Working Group on
Solar Eclipses, I have long worked to bring knowledge about eclipses
and how to observe the safely to the people of the various countries
from which partial, annular, or total solar eclipses are visible. In
2017, we have first a chance to educate the people of South America on
the occasion of the February 26 annular eclipse through southern Chile
and Argentina that is partial throughout almost the entire continent
(and an eclipse workshop will be held February 22-24 in Esquel,
Argentina: http://sion.frm.utn.edu.ar/WDEAII) and then a chance to
educate the 300 million people of the United States and others in
adjacent countries as far south as northern South America about the
glories of totality and how to observe partial phases. Our website,
a compendium of links to information about maps, safe observing,
science, and more is at http://eclipses.info. We link to important
mapping sites at EclipseWise.com, GreatAmericanEclipse.com, and
http://xjubier.free.fr/en/site_pages/solar_eclipses/xSE_GoogleMap3.php?Ecl=+20170821&Acc=2&Umb=1&Lmt=1&Mag=1&Max=1,
and information about cloudiness statistics at
http://eclipsophile.com, as well as simulation sites at
https://svs.gsfc.nasa.gov/cgi-bin/details.cgi?aid=4314 and
http://eyes.jpl.nasa.gov. The American Astronomical Society's task
force on the 2017 eclipse has a website at http://eclipse.aas.org. We
are working to disseminate accurate information about how and why to
observe the total solar eclipse, trying among other things to head
off common misinformation about the hazards of looking at the sun
at eclipses or otherwise. About 12 million Americans live within the
70-mile-wide band of totality, and we encourage others to travel into
it, trying to make clear the difference between even a 99% partial
eclipse and a total eclipse, with its glorious Baily's beads, diamond
rings, and totality that on this occasion lasts between 2 minutes and
2 minutes 40 seconds on the centerline. Our research on the 2017 total
solar eclipse is supported by grants from the Committee for Research
and Exploration of the National Geographic Society and from the Solar
Terrestrial Program of the Atmospheric and Geospace Sciences Division
of the National Science Foundation.
---------------------------------------------------------
Title: The solar corona through the sunspot cycle: preparing for
the August 21, 2017, total solar eclipse
Authors: Pasachoff, Jay M.; Seaton, Daniel; Rusin, Vojtech
2017AAS...22932502P Altcode:
We discuss the evolution of the solar corona as seen at eclipses through
the solar-activity cycle. In particular, we discuss the variations
of the overall shape of the corona through the relative proportions
of coronal streamers at equatorial and other latitudes vs. polar
plumes. We analyze the two coronal mass ejections that we observed
from Gabon at the 2013 total solar eclipse and how they apparently
arose from polar crown filaments, one at each pole. We describe the
change in the Ludendorff flattening index from solar maximum in one
hemisphere as of the 2013 eclipse through the 2015 totality's corona we
observed from Svalbard and, with diminishing sunspot and other magnetic
activity in each hemisphere, through the 2016 corona we observed from
Ternate, Indonesia.We discuss our observational plans for the August
21, 2017, total solar eclipse from our main site in Salem, Oregon,
and subsidiary sites in Madras, OR; Carbondale, IL; and elsewhere,
our main site chosen largely by its favorable rating in cloudiness
statistics. We discuss the overlapping role of simultaneous spacecraft
observations, including those expected not only from NASA's SDO,
ESA's SWAP on PROBA2, and NRL/NASA/ESA's LASCO on SOHO but also from
the new SUVI (Solar Ultraviolet Imager) aboard NOAA's GOES-R satellite,
scheduled as of this writing to have been launched by the time of this
January 2017 meeting.Our research on the 2013 and 2015 total solar
eclipses was supported by grants from the Committee for Research and
Exploration of the National Geographic Society (NG-CRE). Our research
on the 2017 total solar eclipse is supported by both NG-CRE and the
Solar Terrestrial Program of the Atmospheric and Geospace Sciences
Division of the National Science Foundation.
---------------------------------------------------------
Title: The Astrophysics of the Solar Corona at the August 21, 2017,
American Total Solar Eclipse
Authors: Pasachoff, Jay
2017APS..APR.Y3008P Altcode:
The first total solar eclipse to cross the United States from coast to
coast in 99 years will occur on August 21, 2017, with a 70-mile-wide
path of totality from Oregon to South Carolina, with cloudiness
statistics more favorable in the northwest than in the southeast. I
will discuss a series of observations of the solar corona made during
recent solar eclipses and related spacecraft observations. I will
further discuss plans for using the 2017 eclipse for furthering our
studies of the heating of the solar corona to millions of kelvins,
of the dynamics of coronal mass ejections and polar plumes, and of the
response of the corona to the solar magnetic field. I will conclude by
discussing public-education plans for the eclipse, during which the
whole U.S., Mexico, Central America, and Canada will enjoy a partial
eclipse. My work at solar eclipses has recently been supported by the
NSF and the Committee for Research and Exploration of the National
Geographic Society, and I thank them both for research grants for our
scientific studies of the 2017 total eclipse, including AGS-1602461
from the NSF and 987816 from National Geographic.
---------------------------------------------------------
Title: Measuring Bent Starlight
Authors: Pasachoff, Jay
2016S&T...132f...6P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Simon Marius vs. Galileo: Who First Saw Moons of Jupiter?
Authors: Pasachoff, Jay M.; Van Helden, Albert
2016DPS....4831206P Altcode:
In his almanac for 1612 and book Mundus Iovalis of 1614, Simon Marius in
Germany reported his discovery of moons around Jupiter, which he started
writing down in late 1609 in the Julian calendar, which translated to 8
January 1610 in the Gregorian calendar in use by Galileo in Italy. Is
Marius to be believed? Galileo certainly did not. But a Dutch jury of
experts about three hundred years later reported that they validated
the claim that Marius independently discovered the moons of Jupiter one
day after Galileo first both saw and wrote down his discovery! There is
no doubt that the names Io, Europa, Ganymede, and Callisto came from
Marius (to whom they were suggested by Kepler). See JMP's Journal for
the History of Astronomy article, 46(2), 218-234 (2015).Marius wrote
that he had been observing the moons around Jupiter since November 1609
(Julian), using a neighboring nobleman's telescope, which would mean
that he actually saw the Jupiter satellites first (though publish
or perish). Whether this feat was technically possible comes down
to discussions of the capabilities of telescopes in the early 17th
century.The quadricentennial of Marius's book was celebrated in
Nuremberg with a symposium that is now in press in German with an
English translation expected. One of us (AVH) has recently prepared
a complete English translation of Marius's book, superseding the
partial translation made 100 years ago. There is no evidence that,
whether he saw what we now call the Galilean satellites first or not,
Marius appreciated their cosmological significance the way that Galileo
soon did. And Marius was certainly the first to publish tables of the
moons of Jupiter.We thank the Chapin Library of Williams College and
the Huntington Library for assistance with first editions of Marius's
1614 book, and we thank Pierre Leich of the Simon Marius Gesellschaft
for his consultations.
---------------------------------------------------------
Title: The 2016 Transit of Mercury Observed from Major Solar
Telescopes and Satellites
Authors: Pasachoff, Jay M.; Schneider, Glenn; Gary, Dale; Chen, Bin;
Sterling, Alphonse C.; Reardon, Kevin P.; Dantowitz, Ronald; Kopp,
Greg A.
2016DPS....4811705P Altcode:
We report observations from the ground and space of the 9 May 2016
transit of Mercury. We build on our explanation of the black-drop
effect in transits of Venus based on spacecraft observations of the 1999
transit of Mercury (Schneider, Pasachoff, and Golub, Icarus 168, 249,
2004). In 2016, we used the 1.6-m New Solar Telescope at the Big Bear
Solar Observatory with active optics to observe Mercury's transit at
high spatial resolution. We again saw a small black-drop effect as 3rd
contact neared, confirming the data that led to our earlier explanation
as a confluence of the point-spread function and the extreme solar
limb darkening (Pasachoff, Schneider, and Golub, in IAU Colloq. 196,
2004). We again used IBIS on the Dunn Solar Telescope of the Sacramento
Peak Observatory, as A. Potter continued his observations, previously
made at the 2006 transit of Mercury, at both telescopes of the sodium
exosphere of Mercury (Potter, Killen, Reardon, and Bida, Icarus 226,
172, 2013). We imaged the transit with IBIS as well as with two RED
Epic IMAX-quality cameras alongside it, one with a narrow passband. We
show animations of our high-resolution ground-based observations along
with observations from XRT on JAXA's Hinode and from NASA's Solar
Dynamics Observatory. Further, we report on the limit of the transit
change in the Total Solar Irradiance, continuing our interest from
the transit of Venus TSI (Schneider, Pasachoff, and Willson, ApJ 641,
565, 2006; Pasachoff, Schneider, and Willson, AAS 2005), using NASA's
SORCE/TIM and the Air Force's TCTE/TIM. See http://transitofvenus.info
and http://nicmosis.as.arizona.edu.Acknowledgments: We were glad for
the collaboration at Big Bear of Claude Plymate and his colleagues of
the staff of the Big Bear Solar Observatory. We also appreciate the
collaboration on the transit studies of Robert Lucas (Sydney, Australia)
and Evan Zucker (San Diego, California). JMP appreciates the sabbatical
hospitality of the Division of Geosciences and Planetary Sciences of
the California Institute of Technology, and of Prof. Andrew Ingersoll
there. The solar observations lead into the 2017 eclipse studies,
for which JMP is supported by grants from the NSF AGS and National
Geographic CRE.
---------------------------------------------------------
Title: Implications of the Central Flash Analysis from the 2015
Pluto Stellar Occultation
Authors: Person, Michael J.; Bosh, Amanda S.; Sickafoose, Amanda
A.; Zuluaga, Carlos; Levine, Stephen; Pasachoff, Jay M.; Babcock,
Bryce A.; Dunham, Edward W.; McLean, Ian S.; Wolf, Juergen; Abe,
F.; Becklin, Eric E.; Bida, Thomas A.; Bright, Leonard P.; Brothers,
Tim; Christie, Grant; Collins, Peter; Durst, Rebecca; Gilmore, Alan;
Hamilton, Ryan T.; Harris, Hugh C.; Johnson, Christian I.; Kilmartin,
Pam; Kosiarek, Molly; Leppik, Karina; Logsdon, Sarah E.; Lucas, Robert;
Mathers, Shevill; Morley, Caroline; Natusch, T.; Nelson, P.; Ngan, H.;
Pfueller, E.; Roeser, H. -P.; Sallum, Stephanie; Savage, Maureen L.;
Seeger, Christina; Chit Siu, Ho; Stockdale, Christopher; Suzuki, D.;
Thanathibodee, T.; Tilleman, T.; Tristam, P. J.; Van Cleve, Jeffrey
E.; Varughese, C.; Weisenbach, Luke; Widen, E.; Wiedemann, M.
2016DPS....4822404P Altcode:
Two weeks before the historic New Horizons flyby of Pluto, a stellar
occultation was observed from Australia and New Zealand (Bosh et al.,
2016, Pasachoff et al., 2016, Sicardy et al., 2016). Prior to these
observations, an extensive astrometric campaign (Bosh et al., this
meeting) was conducted to carefully place the SOFIA aircraft within the
central flash region of the occultation shadow. Multiple central flash
chords were obtained and initial analysis indicated global asymmetry
of Pluto's atmosphere (Person et al., 2015).Further analysis of these
chords reveals asymmetries in Pluto's atmosphere stronger than those
previously observed by either central flash measurements or occultation
shadow fitting (Person et al., 2006, Olkin et al., 2014). Here we
will discuss this revealed atmospheric asymmetry in terms of the bulk
atmospheric movements necessary to cause distortions of this order,
given the extreme surface sphericity seen by New Horizons (Nimmo et al.,
2016), and its implications for surface ice transport scenarios (Hansen
et al., 2015), and Pluto's seasonal evolution (Earle et al., 2015).
---------------------------------------------------------
Title: The thermal field of the terminator mesosphere of Venus using
solar transit data
Authors: Tanga, Paolo; Widemann, Thomas; Pere, Christophe; Babcock,
Brice A.; Berthier, Jerome; Pasachoff, Jay M.; Roos-Serote, Maarten
2016DPS....4811509T Altcode:
We exploit the solar transits of Venus in 2004 and 2012, to derive
useful constraints on the mesosphere of the planet by the observation
of the so-called "aureole" resulting from direct sunlight refraction. In
2012 we organized an extensive campaign, involving observations through
both space- and ground- based telescopes. A specific design adapted
from the Lyot coronograph was developed and replicated in several
copies to improve the SNR in proximity of the solar disk (Venus
Twilight Experiment).we report on the different data sets collected
during the 2012 transit, and present lightcurve analyses based on
imaging from NASA's Solar Dynamic Observatory (SDO), JAXA's Hinode,
and by the instruments of the Venus Twilight Experiment.We explored
different approaches to model the variation of the aureole brightness,
ranging from simple isothermal modeling to multi-layer.Although less
resolved than the local measurements obtained by Venus Express (SOIR
experiment), aureole modeling has the advantage of being able to cover
simultaneously a wide range of latitudes. We were able to compare the
aureole-derived vertical refractivity profiles to density profiles
obtained simultaneously by SOIR during the transit itself. Our inverse
model, constraining the vertical temperature profiles at all latitudes,
detects a cold layer (at ~86-94 km altitude on average) whose vertical
extent depends on latitude (thicker towards the N pole than at the
Equator), and a latitude-dependent aerosol slanted-opacity altitude
(τ=1).Eventually our model shows that a relevant contribution to the
aureole flux comes from deep layers where aerosol absorption cannot
be neglected, allowing us to put some constraints on the scale height
of aerosol dispersion.
---------------------------------------------------------
Title: First Report on the 2016 March 9 Total Solar Eclipse
Observations
Authors: Pasachoff, Jay M.
2016AAS...22831105P Altcode:
Totality swept across Indonesia and into the Pacific on 2016 March 9,
lasting up to 2 min 45 s on Ternate in the Spice Islands (Malukus). I
provide a first report on our observations. Our scientific goal is
to follow changes in the corona over the solar-activity cycle, now
past its 2012 and 2014 double peak, and to measure temporal changes
in the corona on the scale of minutes or hours by comparing eclipse
observations made at several sites along the path. I also discuss the
near-simultaneous coronal observations made with SOHO/LASCO, SDO/AIA,
STEREO/SECCHI, PROBA2/SWAP, and Hinode XRT.For the forthcoming 2017
eclipse, we acknowledge grants to JMP and Williams College from the
Solar Terrestrial Program of the Atmospheric and Geospace Sciences
Division of the National Science Foundation and from the Committee
for Research and Exploration of the National Geographic Society.
---------------------------------------------------------
Title: Public Education Plans for the 2017 August 21 Total Solar
Eclipse
Authors: Pasachoff, Jay M.
2016AAS...22811201P Altcode:
A total solar eclipse will cross the continental United States on
2017 August 21, the first such in 99 years and the first whose path of
totality on land is entirely in the United States since 1776. People in
the rest of the United States-as well as in Canada, Central America, and
northern South America-will have a partial solar eclipse. Totality will
range up to about 70 km in diameter, and will be visible from a path
that extends from Oregon to South Carolina. Cloudiness statistics
based on decades on satellite infrared imaging are more favorable
for western sites. The sun's diameter will be 80% covered in Miami
(south of totality) and New York (north of totality), and 70% covered
in Los Angeles (south of totality). For the Working Group on Solar
Eclipses of the International Astronomical Union, I maintain a website
at http://eclipses.info that provides links to a wide variety of
eclipse-related material and to useful websites run by others.Prior to
this total eclipse, annular eclipses will cross Africa (from Gabon to
Tanzania and Madagascar) and Isle de la Réunion on 2016 September 1,
and Chile and Argentina on 2017 February 26, at which time we plan
an eclipse workshop in Esquel, Argentina.For the forthcoming 2017
eclipse, we acknowledge grants to JMP and Williams College from the
Solar Terrestrial Program of the Atmospheric and Geospace Sciences
Division of the National Science Foundation and from the Committee
for Research and Exploration of the National Geographic Society.
---------------------------------------------------------
Title: Early Evaluation of the Corona at the 2016 March 9 Total
Solar Eclipse
Authors: Pasachoff, Jay M.; Seaton, Daniel B.; Sterling, Alphonse C.
2016SPD....47.0326P Altcode:
We observed the corona on 2016 March 9 with a variety of assets on
the ground and in space. The umbra of the total eclipse swept across
Indonesia and into the Pacific, with totality at our Indonesian
observation sites lasting 2 min 45 s at Ternate in the Spice Islands
(Malukus) and 2 min 10 at Belitung. We compare our ground-based
results with the coronal configurations observed with PROBA2/SWAP
and Hinode XRT. One of our scientific goals is to follow the coronal
configuration over the solar-activity cycle, with the sunspot number
now half its maximum of either its 2012 or 2014 peak. We are evaluating
temporal changes by comparing eclipse observations made at several
ground-based sites along the path, with the longest span being 75 min
from Belitung to the Woleia atoll in mid-Pacific, 1:25 UTC to 2:40 UTC;
we are evaluating whether the airborne observations made at 3:35 UTC
on March 8 (across the International Dateline) are of suitable quality
to provide further comparison at high spatial resolution. We also
compare our images with the near-simultaneous coronal observations
made with SOHO/LASCO, SDO/AIA, STEREO-A/SECCHI, and the Mauna Loa
Solar Observatory's K-cor coronagraph. ACS received support for image
analysis from the Hinode project.
---------------------------------------------------------
Title: C46 `ASTRONOMY Education and Development': a Peculiar
Commission
Authors: de Greve, Jean-Pierre; García, Beatriz; Gerbaldi, Michèle;
Ferlet, Roger; Guinan, Edward; Hearnshaw, John; Jones, Barrie;
Marschall, Laurence; Miley, George; Pasachoff, Jay; Ros, Rosa;
Stavinschi, Magda; Torres-Peimbert, Silvia
2016IAUTA..29..205D Altcode:
C46 was a Commission of the Executive Committee of the IAU under
Division XII (Union-Wide Activities), then after 2012 under Division C
(Education, Outreach, and Heritage). It was the only commission dealing
exclusively with astronomy education; a previous Commission 38 (Exchange
of Astronomers), which allocated travel grants to astronomers who needed
them, and a Working Group on the Worldwide Development of Astronomy,
have been absorbed by Commission 46.
---------------------------------------------------------
Title: Trio of Stellar Occultations by Pluto One Year Prior to New
Horizons' Arrival
Authors: Pasachoff, Jay M.; Person, Michael J.; Bosh, Amanda S.;
Sickafoose, Amanda A.; Zuluaga, Carlos; Kosiarek, Molly R.; Levine,
Stephen E.; Osip, David J.; Schiff, Avery; Seeger, Christina H.;
Babcock, Bryce A.; Rojo, Patricio; Servajean, Elise
2016AJ....151...97P Altcode:
We observed occultations by Pluto during a predicted series of events
in 2014 July with the 1 m telescope of the Mt. John Observatory in New
Zealand. The predictions were based on updated astrometry obtained in
the previous months at the USNO, CTIO, and Lowell Observatories. We
successfully detected occultations by Pluto of an R = 18 mag star on
July 23 (14:23:32 ± 00:00:04 UTC to 14:25:30 ± 00:00:04 UTC), with a
drop of 75% of the unocculted stellar signal, and of an R = 17 star on
July 24 (11:41:30 ± 00:00:08 UTC to 11:43:28 ± 00:00:08 UTC), with a
drop of 80% of the unocculted stellar signal, both with 20 s exposures
with our frame-transfer Portable Occultation, Eclipse, and Transit
System. Since Pluto had a geocentric velocity of 22.51 km s<SUP>-1</SUP>
on July 23 and 22.35 km s<SUP>-1</SUP> on July 24, these intervals yield
limits on the chord lengths (surface and lower atmosphere) of 2700 ±
130 km and 2640 ± 250 km, respectively, indicating that the events
were near central, and therefore provide astrometric constraints on
the prediction method. Our coordinated observations with the 4 m AAT
in Australia on July 23 and the 6.5 m Magellan/Clay on Las Campanas,
the 4.1 m Southern Astrophysical Research Telescope on Cerro Pachön,
the 2.5 m DuPont on Las Campanas (LCO), the 0.6 m SARA-South on Cerro
Tololo of the Southeastern Association for Research in Astronomy (SARA),
the MPI/ESO 2.2 m on La Silla, and the 0.45 m Cerro Calán telescope
and 0.36 telescope in Constitución in Chile on July 27 and 31, which
would have provided higher-cadence observations for studies of Pluto’s
atmosphere, were largely foiled by clouds, but led to detection with
the LCO Magellan/Clay and DuPont Telescopes on July 31 of the grazing
occultation of a previously unknown 15th-magnitude star, completing the
trio of occultations successfully observed and reported in this paper.
---------------------------------------------------------
Title: The Solar Eclipse Mural Series by Howard Russell Butler
Authors: Pasachoff, J. M.; Olson, R. J. M.
2016ASPC..501...13P Altcode:
There is a rich trove of astronomical phenomena in works of art by
artists from the greater New York area, a trend that is even more
pronounced in the oeuvres of New York City residents through the present
day. A case in point is the trio of oil paintings by artist (and former
physics professor) Howard Russell Butler depicting total solar eclipses
in 1918, 1923, and 1925 that are based on his own observations. They
were long displayed in the former art-deco building of the Hayden
Planetarium of the American Museum of Natural History, the location of
this conference. (The Museum also has nine other Butler paintings, none
of which are currently exhibited.) Since the eclipse paintings have been
in storage for many years, these once famous works are now virtually
forgotten. Based on our research as an astronomer who has seen sixty-two
solar eclipses and an art historian who has written extensively about
astronomical imagery, we will discuss Butler's Solar Eclipse Triptych
to explore its place in the history of astronomical imaging.
---------------------------------------------------------
Title: Structure, Dynamics, and Spectra of the Solar Corona at the
2013 and 2015 Total Eclipses and Plans for 2017's American Totality
Authors: Pasachoff, Jay M.; Dantowitz, Ronald; Voulgaris, Aristeidis
2016AAS...22712502P Altcode:
We observed the total solar eclipses of 3 November 2013 from Gabon and
of 20 March 2015 from Svalbard in clear skies with cameras to image
the solar corona at high resolution and with spectrographs for coronal
emission lines. We report on the composite images showing coronal
structure and (in comparison with other sites' images) dynamics, as
well as the relation of our inner- and middle-corona composite images
with surface EUV images from SDO and SWAP and with the outer-corona
images from the coronagraphs on SOHO/LASCO. Our spectra show not only
the common forbidden lines of Fe XIV (green line) and Fe X (red line)
but also rarer species such as Ca XV. Finally, we describe our planned
suite of observations for the 21 August 2017 solar eclipse, whose path
of totality will cross the United States from Pacific to Atlantic,
with more-favorable cloudiness statistics for western sites.Our Gabon
and Svalbard expeditions were supported by grants from the Committee
for Research and Exploration of the National Geographic Society.
---------------------------------------------------------
Title: Occultation Evidence for Haze in Pluto's Atmosphere in 2015
at the New Horizons Encounter
Authors: Bosh, A. S.; Person, M. J.; Zuluaga, C.; Sickafoose, A. A.;
Levine, S. E.; Pasachoff, J. M.; Babcock, B. A.; Dunham, E. W.;
McLean, I.; Wolf, J.; Abe, F.; Becklin, E.; Bida, T. A.; Bright,
L. P.; Brothers, T.; Christie, G.; Collins, P. L.; Durst, R. F.;
Gilmore, A. C.; Hamilton, R.; Harris, H. C.; Johnson, C.; Kilmartin,
P. M.; Kosiarek, M. R.; Leppik, K.; Logsdon, S.; Lucas, R.; Mathers,
S.; Morley, C. J. K.; Natusch, T.; Nelson, P.; Ngan, H.; Pfüller,
E.; Röser, H. P.; Sallum, S.; Savage, M.; Seeger, C. H.; Siu, H.;
Stockdale, C.; Suzuki, D.; Thanathibodee, T.; Tilleman, T.; Tristram,
P. J.; Van Cleve, J.; Varughese, C.; Weisenbach, L. W.; Widen, E.;
Wiedemann, M.
2015AGUFM.P54A..07B Altcode:
On UT 29 June 2015, the occultation by Pluto of a bright star (r'=11.9)
was observed from the Stratospheric Observatory for Infrared Astronomy
(SOFIA) as well as several ground-based stations in New Zealand and
Australia. Pre-event astrometry allowed for an in-flight update to
the SOFIA team with the result that SOFIA was deep within the central
flash zone. Combined analysis of the data sets leads to the result that
Pluto's middle atmosphere is essentially unchanged from 2011 and 2013
(Person et al. 2013; Bosh et al. 2015); there has been no significant
expansion or contraction of the atmosphere. Additionally, we find that
a haze component in the atmosphere is required to reproduce the light
curves obtained. This haze scenario has implications for understanding
the photochemistry of Pluto's atmosphere. This work was supported
by NASA grants NNX15AJ82G (Lowell Observatory), NNX10AB27G (MIT),
and NNX12AJ29G (Williams), and by the National Research Foundation
of South Africa. Co-authors were visiting observers on SOFIA, at the
Keck Observatory, the Magellan Observatory, the SARA-CT Observatory,
the Mt. John University Observatory, and the Auckland Observatory.
---------------------------------------------------------
Title: Ground-based Light Curves Two Pluto Days Before the New
Horizons Passage
Authors: Bosh, A. S.; Pasachoff, J. M.; Babcock, B. A.; Durst, R. F.;
Seeger, C. H.; Levine, S. E.; Abe, F.; Suzuki, D.; Nagakane, M.;
Sickafoose, A. A.; Person, M. J.; Zuluaga, C.; Kosiarek, M. R.
2015AGUFM.P51A2048B Altcode:
We observed the occultation of a 12th magnitude star, one of the two
brightest occultation stars ever in our dozen years of continual
monitoring of Pluto's atmosphere through such studies, on 29 June
2015 UTC. At Canterbury University's Mt. John University Observatory
on the south island of New Zealand, in clear sky, we used our POETS
frame-transfer CCD at 10 Hz with GPS timing on the 1-m McLellan
telescope as well as an infrared camera on an 0.6-m telescope
and three-color photometry at a slower cadence on a second 0.6-m
telescope. The light curves show a central flash, indicating that we
were close to the center of the occultation path, and allowing us to
explore Pluto's atmosphere lower than usual. The light curves show
that Pluto's atmosphere remained robust. Observations from 0.5- and
0.4-m telescopes at the Auckland Observatory gave the first half of
the occultation before clouds came in. We coordinated our observations
with aircraft observations with NASA's Stratospheric Observatory for
Infrared Astronomy (SOFIA) and its High Speed Imaging Photometer for
Occultations (HIPO). Our ground-based and airborne stellar-occultation
effort came only just over two weeks of Earth days and two Pluto days
(based on Pluto's rotational period) before the flyby of NASA's New
Horizons spacecraft, meaning that the mission's exquisite snapshot
of Pluto's atmosphere can be placed in the context of our series of
ground-based occultation observations carried out on a regular basis
since 2002 following a first Pluto occultation observed in 1988 from
aloft. Our observations were supported by NASA Planetary Astronomy
grants NNX12AJ29G to Williams College, NNX15AJ82G to Lowell Observatory,
and NNX10AB27G to MIT, and by the National Research Foundation of
South Africa. We thank Alan Gilmore, Pam Kilmartin, Robert Lucas,
Paul Tristam, and Carolle Varughese for assistance at Mt. John.
---------------------------------------------------------
Title: Investigation of particle sizes in Pluto's atmosphere from
the 29 June 2015 occultation
Authors: Sickafoose, Amanda A.; Bosh, A. S.; Person, M. J.; Zuluaga,
C. A.; Levine, S. E.; Pasachoff, J. M.; Babcock, B. A.; Dunham,
E. W.; McLean, I.; Wolf, J.; Abe, F.; Bida, T. A.; Bright, L. P.;
Brothers, T.; Christie, G.; Collins, P. L.; Durst, R. F.; Gilmore,
A. C.; Hamilton, R.; Harris, H. C.; Johnson, C.; Kilmartin, P. M.;
Kosiarek, M. R.; Leppik, K.; Logsdon, S.; Lucas, R.; Mathers, S.;
Morley, C. J. K.; Natusch, T.; Nelson, P.; Ngan, H.; Pfüller, E.;
de, H. -P.; Sallum, S.; Savage, M.; Seeger, C. H.; Siu, H.; Stockdale,
C.; Suzuki, D.; Thanathibodee, T.; Tilleman, T.; Tristam, P. J.; Van
Cleve, J.; Varughese, C.; Weisenbach, L. W.; Widen, E.; Wiedemann, M.
2015DPS....4710504S Altcode:
The 29 June 2015 observations of a stellar occultation by Pluto,
from SOFIA and ground-based sites in New Zealand, indicate
that haze was present in the lower atmosphere (Bosh et al., this
conference). Previously, slope changes in the occultation light curve
profile of Pluto’s lower atmosphere have been attributed to haze, a
steep thermal gradient, and/or a combination of the two. The most useful
diagnostic for differentiating between these effects has been observing
occultations over a range of wavelengths: haze scattering and absorption
are functions of particle size and are wavelength dependent, whereas
effects due to a temperature gradient should be largely independent of
observational wavelength. The SOFIA and Mt. John data from this event
exhibit obvious central flashes, from multiple telescopes observing
over a range of wavelengths at each site (Person et al. and Pasachoff
et al., this conference). SOFIA data include Red and Blue observations
from the High-speed Imaging Photometer for Occultations (HIPO, at ~ 500
and 850 nm), First Light Infrared Test Camera (FLITECAM, at ~1800 nm),
and the Focal Plan Imager (FPI+, at ~ 600 nm). Mt. John data include
open filter, g', r', i', and near infrared. Here, we analyze the
flux at the bottom of the light curves versus observed wavelength. We
find that there is a distinct trend in flux versus wavelength, and we
discuss applicable Mie scattering models for different particle size
distributions and compositions (as were used to characterize haze
in Pluto's lower atmosphere in Gulbis et al. 2015).SOFIA is jointly
operated by the Universities Space Research Association, Inc. (USRA),
under NASA contract NAS2-97001, and the Deutsches SOFIA Institut (DSI)
under DLR contract 50 OK 0901 to the University of Stuttgart. Support
for this work was provided by the National Research Foundation of South
Africa, NASA SSO grants NNX15AJ82G (Lowell Observatory), PA NNX10AB27G
(MIT), and PA NNX12AJ29G (Williams College), and the NASA SOFIA Cycle
3 grant NAS2-97001 issued by USRA.
---------------------------------------------------------
Title: The Lunar Profile and Baily's Beads at Solar Eclipses
Authors: Pasachoff, Jay M.; Wright, Ernest T.
2015DPS....4710707P Altcode:
The lunar mapping from NASA's Lunar Reconaissance Orbiter and JAXA's
Kaguya has provided information that allows calculation of the lunar
limb profile whose low points at total solar eclipses provides the
Baily's Beads. Preparations for the forthcoming August 21, 2017, total
solar eclipse (lunar occultation) whose totality crosses the continental
United States from northwest to southeast (http://eclipses.info for
the International Astronomical Union Working Group on Solar Eclipses)
has led to new calculations of the Baily's Beads and of comparisons
of the totality duration between predictions and observations for
historical events.JMP's research on the annular and total solar eclipses
of 2012 was supported in part by the Solar-Terrestrial Program of the
Atmospheric and Geospace Sciences Division of the National Science
Foundation through grant AGS-1047726. His observations of the 2013 and
2015 total solar eclipses were supported by grants 9327-13 and 9616-14,
respectively, from the Committee for Research and Exploration of the
National Geographic Society, with additional support from Williams
College.
---------------------------------------------------------
Title: Preparing for and Observing the 2017 Total Solar Eclipse
Authors: Pasachoff, J.
2015ASPC..500...43P Altcode:
I discuss ongoing plans and discussions for EPO and scientific observing
of the 21 August 2017 total solar eclipse. I discuss aspects of EPO
based on my experiences at the 60 solar eclipses I have seen. I share
cloud statistics along the eclipse path compiled by Jay Anderson,
the foremost eclipse meteorologist. I show some sample observations
of composite imagery, of <P />spectra, and of terrestrial temperature
changes based on observations of recent eclipses, including 2012
from Australia and 2013 from Gabon. Links to various mapping sites of
totality, <P />partial phases, and other eclipse-related information,
including that provided by Michael Zeiler, Fred Espenak (retired from
NASA) and Xavier Jubier can be found on the website I run <P />for
the International Astronomical Union's Working Group on Eclipses at
http://www.eclipses.info.
---------------------------------------------------------
Title: Aeolus: A Markov Chain Monte Carlo Code for Mapping Ultracool
Atmospheres. An Application on Jupiter and Brown Dwarf HST Light
Curves
Authors: Karalidi, Theodora; Apai, Dániel; Schneider, Glenn; Hanson,
Jake R.; Pasachoff, Jay M.
2015ApJ...814...65K Altcode: 2015arXiv151004251K
Deducing the cloud cover and its temporal evolution from the observed
planetary spectra and phase curves can give us major insight into
the atmospheric dynamics. In this paper, we present Aeolus, a Markov
chain Monte Carlo code that maps the structure of brown dwarf and
other ultracool atmospheres. We validated Aeolus on a set of unique
Jupiter Hubble Space Telescope (HST) light curves. Aeolus accurately
retrieves the properties of the major features of the Jovian atmosphere,
such as the Great Red Spot and a major 5 μm hot spot. Aeolus is
the first mapping code validated on actual observations of a giant
planet over a full rotational period. For this study, we applied
Aeolus to J- and H-band HST light curves of 2MASS J21392676+0220226
and 2MASS J0136565+093347. Aeolus retrieves three spots at the top
of the atmosphere (per observational wavelength) of these two brown
dwarfs, with a surface coverage of 21% ± 3% and 20.3% ± 1.5%,
respectively. The Jupiter HST light curves will be publicly available
via ADS/VIZIR.
---------------------------------------------------------
Title: Central Flash Analysis of the 29 June 2015 Occultation
Authors: Person, Michael J.; Bosh, A. S.; Sickafoose, A. A.; Zuluaga,
C. A.; Levine, S. E.; Pasachoff, J. M.; Babcock, B. A.; Dunham, E. W.;
McLean, I.; Wolf, J.; Abe, F.; Becklin, E.; Bida, T. A.; Bright, L. P.;
Brothers, T. C.; Christie, G.; Collins, P. L.; Durst, R. F.; Gilmore,
A. C.; Hamilton, R.; Harris, H. C.; Johnson, C.; Kilmartin, P. M.;
Kosiarek, M. R.; Leppik, K.; Logsdon, S. E.; Lucas, R.; Mathers,
S.; Morley, C. J. K.; Natusch, T.; Nelson, P.; Ngan, H.; Pfueller,
E.; Roeser, H. -P.; Sallum, S.; Savage, M.; Seeger, C. H.; Siu, H.;
Stockdale, C.; Suzuki, D.; Thanathibodee, T.; Tilleman, T.; Tristram,
P. J.; Van Cleeve, J.; Varughese, C.; Weisenbach, L. W.; Widen, E.;
Wiedemann, M.
2015DPS....4710505P Altcode:
After an extensive prediction effort, the 29 June 2015 occultation
by Pluto was observed from both airborne (Stratospheric Observatory
for Infrared Astronomy - SOFIA) and numerous ground-based telescopes
(Bosh et al. - this meeting). Real-time prediction updates allowed
placement of the SOFIA telescope with its four detectors deep within the
central-flash region of the atmospheric occultation. Fortuitously, the
Mount John University Observatory (Lake Tekapo, New Zealand) was also
within the central-flash region (Pasachoff et al. - this meeting). This
happenstance resulted in multiple central-flash detections in several
colors from each facility allowing direct comparison of different
areas of the central-flash evolute.Here we examine and discuss the
central-flash signatures from the highest signal-to-noise light curves
from each facility. The relative orientations and asymmetries in the
central flashes allow us to use them to tightly constrain the lower
atmospheric ellipticity and orientation of likely winds with respect
to Pluto’s figure. The ratio of the two separate central flashes
is also a strong constraint on the geometric solution for the full
occultation data set, and the absolute height of the central flashes
with respect to those expected for a clear isothermal atmosphere places
constraints on haze densities and thermal gradients in Pluto’s lower
atmosphere. We can also compare the central-flash signatures in several
colors (similar to Sickafoose et. al - this meeting) to establish
bounds on haze-particle sizes in the lower atmosphere.SOFIA is jointly
operated by the Universities Space Research Association, Inc. (USRA),
under NASA contract NAS2-97001, and the Deutsches SOFIA Institut (DSI)
under DLR contract 50 OK 0901 to the University of Stuttgart. Support
for this work was provided, in part, by NASA grants SSO NNX15AJ82G
(Lowell Observatory), PA NNX10AB27G (MIT), and PA NNX12AJ29G (Williams
College), as well as the National Research Foundation of South Africa,
and the NASA SOFIA Cycle 3 grant NAS2-97001 issued by USRA.
---------------------------------------------------------
Title: Haze in Pluto's atmosphere: Results from SOFIA and ground-based
observations of the 2015 June 29 Pluto occultation
Authors: Bosh, A. S.; Person, M. J.; Zuluaga, C. A.; Sickafoose,
A. A.; Levine, S. E.; Pasachoff, J. M.; Babcock, B. A.; Dunham, E. W.;
McLean, I.; Wolf, J.; Abe, F.; Becklin, E.; Bida, T. A.; Bright, L. P.;
Brothers, T.; Christie, G.; Collins, P. L.; Durst, R. F.; Gilmore,
A. C.; Hamilton, R.; Harris, H. C.; Johnson, C.; Kilmartin, P. M.;
Kosiarek, M. R.; Leppik, K.; Logsdon, S. E.; Lucas, R.; Mathers,
S.; Morley, C. J. K.; Nelson, P.; Ngan, H.; Pfüller, E.; Natusch,
T.; Röser, H. -P.; Sallum, S.; Savage, M.; Seeger, C. H.; Siu, H.;
Stockdale, C.; Suzuki, D.; Thanathibodee, T.; Tilleman, T.; Tristram,
P. J.; Van Cleve, J.; Varughese, C.; Weisenbach, L. W.; Widen, E.;
Wiedemann, M.
2015DPS....4710503B Altcode:
We observed the 29 June 2015 occultation by Pluto from SOFIA and several
ground-based sites in New Zealand. Pre-event astrometry (described
in Zuluaga et al., this conference) allowed us to navigate SOFIA into
Pluto's central flash (Person et al., this conference). Fortuitously,
the central flash also fell over the Mt. John University Observatory
(Pasachoff et al., this conference). We combine all of our airborne and
ground-based data to produce a geometric solution for the occultation
and to investigate the state of Pluto's atmosphere just two weeks
before the New Horizons spacecraft's close encounter with Pluto. We
find that the atmosphere parameters at half-light are unchanged
from our observations in 2011 (Person et al. 2013) and 2013 (Bosh
et al. 2015). By combining our light-curve inversion with recent
radius measurements from New Horizons, we find strong evidence for
an extended haze layer in Pluto's atmosphere. See also Sickafoose
et al. (this conference) for an evaluation of the particle sizes
and properties.SOFIA is jointly operated by the Universities Space
Research Association, Inc. (USRA), under NASA contract NAS2-97001,
and the Deutsches SOFIA Institut (DSI) under DLR contract 50 OK 0901
to the University of Stuttgart. Support for this work was provided by
NASA SSO grants NNX15AJ82G (Lowell Observatory), NNX10AB27G (MIT), and
NNX12AJ29G (Williams College), and by the National Research Foundation
of South Africa.
---------------------------------------------------------
Title: A Central Flash at an Occultation of a Bright Star by Pluto
Soon Before New Horizons' Flyby
Authors: Pasachoff, Jay M.; Babcock, Bryce A.; Durst, Rebecca F.;
Seeger, Christina H.; Levine, Stephen E.; Bosh, Amanda S.; Sickafoose,
Amanda A.; Person, Michael J.; Abe, Fumio; Suzuki, Daisuke; Nagakane,
Masayuki; Tristam, Paul J.
2015DPS....4721012P Altcode:
From the Mt. John Observatory, New Zealand, we were so close to
the center of the occultation path on 29 June 2015 UTC that we
observed a modest central flash from the focusing of starlight from
a 12th-magnitude star. The star was one of the brightest ever in our
years of continual monitoring that started in 2002. At the time of
Pluto's perihelion in 1989, it was feared from models that Pluto's
atmosphere might collapse by now, a motivation for the timely launch
of New Horizons; some models now allow Pluto to retain its atmosphere
throughout its orbit.We used our frame-transfer CCD at 10 Hz with
GPS timing on the 1-m McLellan telescope of Canterbury U. We also
observed with a Lowell Obs. infrared camera on the "AAVSO" 0.6-m Optical
Craftsman telescope; and obtained 3-color photometry at a slower cadence
on a second 0.6-m telescope. We coordinated with the overflight of SOFIA
and its 2.5-m telescope, which benefited from last-minute astrometry,
and the Auckland Observatory's and other ground-based telescopes.Our
light curves show a modest central flash; our tentative geometrical
solution shows that we were only about 50 km from the occultation path's
centerline. The flash is from rays lower than otherwise accessible
in Pluto's atmosphere. Our light curves, at such high cadence that we
see spikes caused by atmospheric effects that we had not seen so well
since our 2002 Mauna Kea occultation observations, show that Pluto's
atmosphere had not changed drastically since our previous year's
observations. Our data provide a long-term context for New Horizon's
highly-detailed observations of Pluto's atmosphere in addition to
providing a chord for the geometrical solution that includes SOFIA's
observations.Our observations were supported by NASA Planetary Astronomy
grants NNX12AJ29G to Williams College, NNX15AJ82G to Lowell Observatory,
and NNX10AB27G to MIT, and by the National Research Foundation of South
Africa. We are grateful to Alan Gilmore, Pam Kilmartin, Robert Lucas,
and Carolle Varughese for assistance at Mt. John. We thank the AAVSO
for use of the AAVSOnet 0.6-m telescope and Arne Henden for assistance.
---------------------------------------------------------
Title: Report of the IAU Working Group on Solar Eclipses
Authors: Pasachoff, Jay M.
2015IAUGA..2254605P Altcode:
The Working Group on Solar Eclipses coordinates scientists and
information in the study of the Sun and the heliosphere at solar
eclipses. Our Website at http://eclipses.info has a wide variety
of information, including links to maps and other websites dealing
with solar eclipses, as well as information on how to observe the
partial-phases of solar eclipses safely and why it is interesting
for not only scientists but also for the public to observe eclipses
and to see how we work to uncover the mysteries of the sun's upper
atmosphere. In the last triennium, there were total eclipses in
Australia and the Pacific in 2012; in an arc across Africa from Gabon
to Uganda and Kenya in 2013; and in the Arctic, including Svalbard
and the Faeroes plus many airplanes aloft, in 2015. In the coming
triennium, there will be total solar eclipses in Indonesia and the
Pacific in 2016 and then, on 21 August 2017, a total solar eclipse
that will sweep across the Continental United States from northwest
to southeast. Mapping websites, all linked to http://eclipses.info,
include Fred Espenak's http://EclipseWise.com; Michael Zeiler's
http://GreatAmericanEclipse.com and http://eclipse-maps.com; Xavier
Jubier's http://xjubier.free.fr; and (with weather and cloudiness
analysis) Jay Anderson's http://eclipser.ca. Members of the Working
Group, chaired by Jay Pasachoff (U.S.), include Iraida Kim (Russia),
Kiroki Kurokawa (Japan), Jagdev Singh (India), Vojtech Rusin (Slovakia),
Zhongquan Qu (China), Fred Espenak (U.S.), Jay Anderson (Canada),
Glenn Schneider (U.S.), Michael Gill (U.K.), Xavier Jubier (France),
Michael Zeiler (U.S.), and Bill Kramer (U.S.).
---------------------------------------------------------
Title: Public Education and Outreach for Observing Solar Eclipses
and Transits
Authors: Pasachoff, Jay M.
2015IAUGA..2254684P Altcode:
The general public is often very interested in observing solar eclipses,
with widespread attention from newspapers and other sources often
available only days before the events. Recently, the 2012 eclipse's
partial phases in Australia and the 2015 eclipse's partial phases
throughout Europe as well as western Asia and northern Africa, were
widely viewed. The 21 August 2017 eclipse, whose totality will sweep
across the Continental United States from northwest to southeast,
will have partial phases visible throughout the U.S., Canada, Mexico,
Central America, and into South America. The 2019 and 2020 partial
phases of total eclipses will be visible throughout South America,
and partial phases from annular eclipses will be visible from other
parts of the world. The 9 May 2016 transit of Mercury will be best
visible from the Western Hemisphere, Europe, and Africa. Many myths and
misunderstandings exist about the safety of observing partial phases,
and it is our responsibility as astronomers and educators to transmit
accurate information and to attempt the widest possible distribution
of such information. The Working Group on Public Education at Eclipses
and Transits, formerly of Commission 46 on Education and Development
and now of New Commission 11, tries to coordinate the distribution of
information. In collaboration with the Solar Division's Working Group
on Solar Eclipses, their website at http://eclipses.info is a one-stop
shop for accurate information on how to observe eclipses, why it is
interesting to do so, where they will be visible (with links to online
maps and weather statistics), and how encouraging students to observe
eclipses can be inspirational for them, perhaps even leading them to
realize that the Universe can be understood and therefore renewing
the strength of their studies. Links to information about transits of
Mercury and Venus are also included.
---------------------------------------------------------
Title: Division XII: Commission 46: Education & Development
of Astronomy
Authors: Ros, Rosa M.; Hearnshaw, John; Stavinschi, Magda; Garcia,
Beatriz; Gerbaldi, Michele; de Greve, Jean-Pierre; Guinan, Edward;
Haubold, Hans; Jones, Barrie; Marshall, Laurence A.; Pasachoff, Jay
2015IAUTB..28..137R Altcode:
C46 is a Commission of the Executive Committee of the IAU under Division
XII Union-Wide Activities. Aiming at improvement of astronomy education
and research at all levels worldwide (through the various projects it
initiates),maintains, develops, as well as through the dissemination of
information. C46 has 332 members and it was managed by the Organizing
Committee, formed by the Commission President (Rosa M. Ros, from Spain),
the Vice-Presiden (John Hearnshaw, from New Zealand), the Retiring
President (Magda Stavinschi, from Romania), the Vice-President of the
IAU (George Miley, from Netherland) and the PG chairs: • Worldwide
Development of Astronomy WWDA: John Hearnshaw • Teaching Astronomy
for Development TAD: Edward Guinan and Laurence A. Marshall •
International Schools for Young Astronomers ISYA; chair: Jean-Pierre de
Greve • Network for Astronomy School Education NASE: Rosa M. Ros and
Beatriz Garcia • Public Understanding at the times of Solar Eclipses
and transit Phenomena PUTSE: Jay Pasachoff • National Liaison and
Newsletter: Barrie Jones • Collaborative Programs: Hans Haubold
---------------------------------------------------------
Title: Book review: Nearest Star: The surprising science of our Sun
(Golub & Pasachoff)
Authors: Smith, L.; Golub, L.; Pasachoff, J. M.
2015JBAA..125..183S Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Simon Marius's Mundus Iovialis: 400th Anniversary in Galileo's
Shadow
Authors: Pasachoff, Jay M.
2015JHA....46..218P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The Solar Corona at the 2015 Total Solar Eclipse
Authors: Pasachoff, Jay M.; Carter, Allison L.
2015TESS....120319P Altcode:
We report on our successful observations of the solar corona at the 20
March 2015 total solar eclipse from our site at a latitude of about 78°
on the Svalbard archipelago, and related observations by colleagues
aloft. Our equipment included cameras for imaging at a variety of
scales for use in making high-contrast composites, as reported our
Astrophysical Journal article (2015) about our 2012 total solar eclipse
observations and similar articles about the corona and changes in it
at previous total eclipses. Our Svalbard equipment also included a
spectrograph, with which we continued our monitoring of the ratio of
the Fe XIV and Fe X coronal lines, which has recently been >1 with
the solar maximum, a reversal from <1 at earlier eclipses closer to
the last solar minimum. Our 2013 observations from Gabon showed two
coronal mass ejections and an erupting prominence; the 2015 eclipse
showed an erupting prominence and some unusual coronal structure in an
overall coronal shape typical of solar maximum. We use our ground-based
eclipse observations to fill the gap in imaging between the SDO and SWAP
(17.4 nm) EUV observations on the solar disk and the inner location
of the LASCO C2 occultation disk, with STEREO observations providing
the possibility of three-dimensional interpretations. Our expedition
was supported by a grant (9616-14) from the Committee for Research
and Exploration of the National Geographic Society.
---------------------------------------------------------
Title: Air-cooling mathematical analysis as inferred from the
air-temperature observation during the 1st total occultation of the
Sun of the 21st century at Lusaka, Zambia
Authors: Peñaloza-Murillo, Marcos A.; Pasachoff, Jay M.
2015JASTP.125...59P Altcode:
We analyze mathematically air temperature measurements made near the
ground by the Williams College expedition to observe the first total
occultation of the Sun [TOS (commonly known as a total solar eclipse)]
of the 21st century in Lusaka, Zambia, in the afternoon of June 21,
2001. To do so, we have revisited some earlier and contemporary methods
to test their usefulness for this analysis. Two of these methods, based
on a radiative scheme for solar radiation modeling and that has been
originally applied to a morning occultation, have successfully been
combined to obtain the delay function for an afternoon occultation,
via derivation of the so-called instantaneous temperature profiles. For
this purpose, we have followed the suggestion given by the third of
these previously applied methods to calculate this function, although by
itself it failed to do so at least for this occultation. The analysis
has taken into account the limb-darkening, occultation and obscuration
functions. The delay function obtained describes quite fairly the lag
between the solar radiation variation and the delayed air temperature
measured. Also, in this investigation, a statistical study has been
carried out to get information on the convection activity produced
during this event. For that purpose, the fluctuations generated by
turbulence has been studied by analyzing variance and residuals. The
results, indicating an irreversible steady decrease of this activity,
are consistent with those published by other studies. Finally, the air
temperature drop due to this event is well estimated by applying the
empirical scheme given by the fourth of the previously applied methods,
based on the daily temperature amplitude and the standardized middle
time of the occultation. It is demonstrated then that by using a simple
set of air temperature measurements obtained during solar occultations,
along with some supplementary data, a simple mathematical analysis
can be achieved by applying of the four methods reviewed here.
---------------------------------------------------------
Title: Book Review: Eclipses, Transits, and Comets of the Nineteenth
Century: How America's Perceptions of the Skies Changed
Authors: Pasachoff, Jay M.
2015JAHH...18..112P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Structure and Dynamics of the 2012 November 13/14 Eclipse
White-light Corona
Authors: Pasachoff, J. M.; Rušin, V.; Saniga, M.; Babcock, B. A.;
Lu, M.; Davis, A. B.; Dantowitz, R.; Gaintatzis, P.; Seiradakis,
J. H.; Voulgaris, A.; Seaton, D. B.; Shiota, K.
2015ApJ...800...90P Altcode: 2014arXiv1412.1155P
Continuing our series of observations of coronal motion and dynamics
over the solar-activity cycle, we observed from sites in Queensland,
Australia, during the 2012 November 13 (UT)/14 (local time) total
solar eclipse. The corona took the low-ellipticity shape typical of
solar maximum (flattening index ɛ = 0.01), a change from the composite
coronal images we observed and analyzed in this journal and elsewhere
for the 2006 and 2008-2010 eclipses. After crossing the northeast
Australian coast, the path of totality was over the ocean, so further
totality was seen only by shipborne observers. Our results include
velocities of a coronal mass ejection (CME; during the 36 minutes of
passage from the Queensland coast to a ship north of New Zealand, we
measured 413 km s<SUP>-1</SUP>) and we analyze its dynamics. We discuss
the shapes and positions of several types of coronal features seen on
our higher-resolution composite Queensland coronal images, including
many helmet streamers, very faint bright and dark loops at the bases
of helmet streamers, voids, and radially oriented thin streamers. We
compare our eclipse observations with models of the magnetic field,
confirming the validity of the predictions, and relate the eclipse
phenomenology seen with the near-simultaneous images from NASA's Solar
Dynamics Observatory (SDO/AIA), NASA's Extreme Ultraviolet Imager
on Solar Terrestrial Relations Observatory, ESA/Royal Observatory
of Belgium's Sun Watcher with Active Pixels and Image Processing
(SWAP) on PROBA2, and Naval Research Laboratory's Large Angle and
Spectrometric Coronagraph Experiment on ESA's Solar and Heliospheric
Observatory. For example, the southeastern CME is related to the solar
flare whose origin we trace with a SWAP series of images.
---------------------------------------------------------
Title: 400th Anniversary of Marius's Book with the First Image of
an Astronomical Telescope and of Orbits of Jovian Moons
Authors: Pasachoff, Jay M.; Leich, Pierre
2015AAS...22521505P Altcode:
Simon Mayr's (Marius's) Mundus Iovialis Anno M·DC·IX Detectus
Ope Perspicilli Belgici (The World of Jupiter...) was published in
Nuremberg in 1614; Marius was the Ansbach court mathematician. The
frontispiece includes not only a portrait of Marius (1573-1624) himself
but also, in the foreground, a long tube labelled "perspicillum,"
the first known image of a telescopic device used for astronomy;
the name "telescope" came later. A schematic diagram of Jupiter
with four moons orbiting appears at upper left; Marius, following
a suggestion from Kepler, gave these Galilean satellites the names
now still in use: Io, Europa. Ganymede, and Callisto. The title
continues Hoc est, Quatuor Joviali cum Planetarum, cum Theoria,
tum Tabulae, Propriis Observationibus Maxime Fundate.... A pair
of conferences was held in Germany in 2014 to commemorate the
400th anniversary of Marius's book and to discuss Marius's work
and its relation to Galileo's work (http://www.simon-marius.net;
http://www.simon-marius.net/index.php?lang=en&menu=1 28 languages
are available). Marius (Mayr) had independently discovered the four
satellites of Jupiter, apparently one day after Galileo, on December
29 O.S., 1609; by the time he published his work four years later
(a local-circulation publication had appeared in Nuremberg in 1611
in Prognosticon Astrologicum auf das Jahr 1612), Galileo had gained
fame and priority, and Galileo accused Marius of plagiarism in Il
Saggiatore (1623). With his Belgian telescope, Marius also noted the
tilt of the orbital plane of Jupiter's moons, sunspots (1611), and
the Andromeda Nebula (1612). He claimed to have worked out a system of
cosmology similar to the Tychonic system in 1596, contemporaneously to
Kepler's Mysterium Cosmographicum. A crater, the Marius Hills, and the
Rima Marius on the Moon are named for him by the I.A.U., as well as,
to celebrate the quadricentennial, a main-belt asteroid, now (7984)
Marius. Acknowledgment: JMP thanks Seth Fagen, PRPH Books in New York,
for introducing him to Marius's book 18 years ago.
---------------------------------------------------------
Title: Trio of stellar occultations by Pluto One Year Prior to New
Horizons' Arrival
Authors: Pasachoff, Jay M.; Person, Michael J.; Bosh, Amanda S.;
Gulbis, Amanda A. S.; Zuluaga, Carlos A.; Levine, Stephen; Osip,
David J.; Schiff, Adam R.; Seeger, Christina H.; Babcock, Bryce A.;
Rojo, Patricio; Kosiarek, Molly R.; Servajean, Elise
2015AAS...22513715P Altcode:
Our campaign in July 2014 yielded three successful stellar occultations
(~m=15, 17, and 18) of Pluto (~m=14), observed from telescopes in New
Zealand, Australia, and Chile. Telescopes involved included Chile:
Magellan's Clay (6.5 m), SOAR (4.1 m), Carnegie's DuPont (2.4 m);
Australia: AAT (4 m); and Canterbury's Mt. John McLellan (1-m); as well
as various smaller telescopes in Australia and Chile. One of the events
was also observed, with negative results, from GROND on La Silla (2.2
m) and SMARTS's ANDICAM at CTIO (1.3 m). Though our observations were
coordinated across continents, each successfully observed event was
seen from only one site because of bad weather at the other sites. Two
of the events were uniquely observed from Mt. John (Pasachoff et al.,
DPS 2014) and one, with only Chile sites in the predicted path, from
the Clay (Person et al., DPS 2014). This last event was expected to be
of the brightest star with the largest telescope we have ever observed
for a Pluto occultation, but clouds arrived at the 6.5-m Clay 90 s
before the predicted time; a 1% occultation was nonetheless seen and
eventually, confirmed by Keck AO observations, to be of a 15th magnitude
star previously hidden in the brightness of the 12th mag star. Our
scientific conclusion is that as of these observations, one year before
New Horizons' passage of Pluto, the atmosphere of Pluto remained robust
and of the same size. Details on our analysis of the three events will
be presented.Acknowledgments: This work was supported in part by NASA
Planetary Astronomy grants to Williams College (NNX12AJ29G) and to
MIT (NNX10AB27G), as well as grants from USRA (#8500-98-003) and Ames
Research (#NAS2-97-01) to Lowell Observatory. A.R.S. was supported by
NSF grant AST-1005024 for the Keck Northeast Astronomy Consortium REU,
with partial support from U.S. DoD's ASSURE program. P.R. acknowledges
support from FONDECYT through grant 1120299. J.M.P. thanks Andrew
Ingersoll and Caltech Planetary Astronomy for hospitality.
---------------------------------------------------------
Title: Observations of a successive stellar occultation by Charon
and graze by Pluto in 2011: Multiwavelength SpeX and MORIS data from
the IRTF
Authors: Gulbis, A. A. S.; Emery, J. P.; Person, M. J.; Bosh, A. S.;
Zuluaga, C. A.; Pasachoff, J. M.; Babcock, B. A.
2015Icar..246..226G Altcode:
Pluto's lower atmosphere has been observed to evolve since the
first definitive occultation detection in 1988. Possibilities for
explaining the lower atmospheric structure include a steep thermal
gradient and/or extinction, the latter of which can be characterized
as a dependence between occultation flux and wavelength. On 2011
June 23, a 14.43 UCAC magnitude star (R = 13.64) was occulted by
Pluto as observed from multiple sites. Observations made at NASA's 3-m
Infrared Telescope Facility (IRTF) on Mauna Kea, Hawai'i, showed a full
occultation of the star by Charon followed by an atmospheric graze by
Pluto. Data were taken simultaneously in visible-wavelength images and
low-resolution, near-infrared spectra. This dataset is unique in that
(i) the double occultation allows astrometric measurements for Pluto
and Charon as well as accurate calibration of the Pluto light curve,
and (ii) the wavelength-resolved data serve as a test for atmospheric
extinction. The graze reached a minimum normalized flux level of roughly
0.35, serving primarily as a probe of Pluto's upper atmosphere (which
is typically defined to be above half-light level in occultation light
curves). However, the light curve is well fit by atmospheric models
with a power-law thermal gradient, a clear upper atmosphere, and haze
in the lower atmosphere. We find a negative dependence between flux
and wavelength in the deepest part of Pluto's atmosphere probed by the
graze and in a spike during emersion. A simple extinction model for
spherical, μm-sized tholins matches the observed spectral trends. While
the atmospheric fits cannot rule out a clear atmosphere having a steep
thermal gradient at the bottom, the flux-wavelength dependence and the
feasibility of our particle-scattering fits suggest that Pluto's lower
atmosphere contained haze in 2011. These results provide an important
link in monitoring Pluto's dynamic atmosphere.
---------------------------------------------------------
Title: The state of Pluto's atmosphere in 2012-2013
Authors: Bosh, A. S.; Person, M. J.; Levine, S. E.; Zuluaga, C. A.;
Zangari, A. M.; Gulbis, A. A. S.; Schaefer, G. H.; Dunham, E. W.;
Babcock, B. A.; Davis, A. B.; Pasachoff, J. M.; Rojo, P.; Servajean,
E.; Förster, F.; Oswalt, T.; Batcheldor, D.; Bell, D.; Bird, P.; Fey,
D.; Fulwider, T.; Geisert, E.; Hastings, D.; Keuhler, C.; Mizusawa,
T.; Solenski, P.; Watson, B.
2015Icar..246..237B Altcode:
We observed two stellar occultations on UT 4 May 2013 and UT 9 September
2012, with the aim of measuring Pluto's atmospheric parameters. Both
of these events were observed by world-wide collaborations of many
observers, and both occurred within 1 month of Pluto's stationary
points. The PC20120909 event was observed at the McDonald Observatory
(MONET 1.2-m), and Olin Observatory (the Ortega 0.8-m); the P20130504
event was observed at the Las Campanas Observatory (du Pont 2.5-m),
the Cerro Tololo Inter-American Observatory (SMARTS 1-m), and the Cerro
Calán National Astronomical Observatory (Goto 0.45-m). Analysis of the
data indicates an atmospheric state similar to that in June 2011. The
shadow radius for the event is unchanged from recent events, indicating
an atmosphere that is holding stable and not in the midst of global
collapse. We discuss the advantages and disadvantages of comparing
various atmospheric parameters across events (the shadow radius vs. the
pressure at a particular radius). These analyses suggest that Pluto
will still have an atmosphere when the New Horizons spacecraft arrives
in July 2015.
---------------------------------------------------------
Title: Coronal Dynamics at Recent Total Solar Eclipses
Authors: Pasachoff, J. M.; Lu, M.; Davis, A. B.; Demianski, M.; Rusin,
V.; Saniga, M.; Seaton, D. B.; Lucas, R.; Babcock, B. A.; Dantowitz,
R.; Gaintatzis, P.; Seeger, C. H.; Malamut, C.; Steele, A.
2014AGUFMSH41B4144P Altcode:
Our composite images of the solar corona based on extensive imaging at
the total solar eclipses of 2010 (Easter Island), 2012 (Australia),
and 2013 (Gabon) reveal several coronal mass ejections and other
changes in coronal streamers and in polar plumes. Our resultant spatial
resolution is finer than that available in imaging from spacecraft,
including that from SOHO/LASCO or STEREO. We trace the eruptions back
to their footpoints on the sun using imaging from SDO and SWAP, and
follow them upwards through the corona, measuring velocities. The
high-resolution computer compositing by Miloslav Druckmüller and
Hana Druckmüllerová (2010 and 2013) and Pavlos Gaintatzis (2012)
allows comparison of our images with those taken at intervals of
minutes or hours along the totality path. <P />Williams College's 2013
eclipse expedition was supported in part by grant 9327-13 from National
Geographic Society/Committee for Research and Exploration. Our work on
the 2012 eclipse is supported in part by grant AGS-1047726 from Solar
Terrestrial Research/NSF AGS. V.R. and M.S. were partially supported by
the VEGA grant agency project 2/0098/10 and 2/0003/13 (Slovak Academy
of Sciences) and Grant 0139-12 from NG/CRE, and Hana Druckmüllerová by
grant 205/09/1469 of the Czech Science Foundation. M.L. was supported by
Sigma Xi. C.M. was a Keck Northeast Astronomy Consortium Summer Fellow,
supported at Williams College by REU/NSF grant AST-1005024. Partial
support was provided by U.S. Department of Defense's ASSURE
program. J.M.P. thanks Caltech's Planetary Sciences Department for
hospitality. Support for D.B.S. and SWAP came from PRODEX grant C90345
managed by ESA in collaboration with the Belgian Federal Science Policy
Office (BELSPO) in support of the PROBA2/SWAP mission, and from the
EC's Seventh Framework Programme (FP7/2007-2013) under grant 218816
(SOTERIA project, www.soteria-space.eu). SWAP is a project of the Centre
Spatial de Liège and the Royal Observatory of Belgium funded by BELSPO.
---------------------------------------------------------
Title: Coordinated Occultation Observations for Pluto, Nix, and
Quaoar in July 2014
Authors: Pasachoff, Jay M.; Schiff, Adam R.; Seeger, Christina H.;
Babcock, Bryce A.; Person, Michael J.; Gulbis, Amanda A. S.; Bosh,
Amanda S.; Zuluaga, Carlos A.; Levine, Stephen E.; Osip, David J.;
Rojo, Patricio; Kosiarek, Molly
2014DPS....4641901P Altcode:
We observed Pluto, its moon Nix, and Quaoar during a predicted series
of occultations in July 2014 with the 1-m telescope of the Mt. John
University Observatory in New Zealand. The observations were based on
new USNO photometry. We successfully detected occultations by Pluto
of an R=18 mag star on 23 July (14:23:30 ± 00:00:10 UTC to 14:25:30
± 00:00:10 UTC), with a drop of 5%, and of an R=17 star on 24 July
(11:41:30 ± 00:00:10 UTC to 11:43:30 ± 00:00:10 UTC), with a drop of
3%, both with 20 s exposures with our frame-transfer POETS. Since Pluto
had a geocentric velocity of 22.51 km/s on 23 July and 22.35 km/s on
24 July, these intervals yield limits on the chord lengths (surface +
lower atmosphere) of 2700 ± 130 km and 2640 ± 250 km respectively,
indicating that the events were near central, and provide astrometric
data. Our coordinated observations with the 4-m AAT in Australia
on 23 July and the 6.5-m Magellan/Clay, the 4.1-m SOAR, the 2.5-m
DuPont, the 0.6-m SARA South, and the 0.45-m Cerro Calán telescopes
in Chile on July 27 and 31, which would have provided higher-cadence
observations for studies of Pluto’s atmosphere, were largely foiled
by clouds.This work was supported in part by NASA Planetary Astronomy
grants to Williams College (NNX12AJ29G) and to MIT (NNX10AB27G), as
well as grants from USRA (#8500-98-003) and Ames Research (#NAS2-97-01)
to Lowell Observatory. A.R.S. was supported by NSF grant AST-1005024
for the Keck Northeast Astronomy Consortium REU, with partial support
from U.S. DoD's ASSURE program. P.R. acknowledges support from FONDECYT
through grant 1120299.
---------------------------------------------------------
Title: Evidence of Haze in Pluto’s Lower Atmosphere in 2011
Authors: Gulbis, Amanda; Emery, Joshua P.; Person, Michael J.; Bosh,
Amanda S.; Zuluaga, Carlos A.; Pasachoff, Jay M.
2014DPS....4640101G Altcode:
Based on stellar occultation observations since 1988, Pluto’s
lower atmosphere has been evolving (e.g., Elliot et al. 2007, AJ,
134, 1; Young et al. 2008, AJ, 136, 1757; Bosh et al. 2014, Icarus,
in press). The structure of the lower atmosphere is likely due to a
steep thermal gradient and/or extinction, the latter of which can be
characterized as a dependence between observed occultation flux and
wavelength. On 2011 June 23, a 13.64 R-magnitude star was occulted by
Pluto as observed from multiple sites (Person et al. 2013, AJ, 146,
83). Observations made at NASA’s 3-m Infrared Telescope Facility
(IRTF) on Mauna Kea, Hawai’i, showed a full occultation of the
star by Charon followed by an atmospheric graze by Pluto. Data were
taken simultaneously in visible-wavelength images and low-resolution,
near-infrared spectra. This unique, wavelength-resolved dataset serves
as a test for atmospheric extinction. The graze primarily probed
Pluto’s upper atmosphere. The upper atmosphere is typically defined
to be above half-light level in occultation light curves (approximately
three pressure scale heights above the surface), and the graze reached a
minimum of roughly 0.35 flux. However, the light curve is well matched
by an atmospheric model with a power-law thermal gradient, a clear
upper atmosphere, and haze in the lower atmosphere. Furthermore,
there is a negative dependence between flux and wavelength in the
deepest part of the atmosphere probed by the graze, as well as in an
emersion spike. We find that a simple extinction model for spherical,
micron-sized tholins matches the observed spectral trends (Gulbis
et al. 2014, Icarus, in press). While the atmospheric fits cannot
rule out a clear atmosphere having a steep thermal gradient at the
bottom, the flux-wavelength dependence and the feasibility of our
particle-scattering fits suggest that Pluto’s lower atmosphere
contained haze in 2011. These results provide an important link in
monitoring Pluto’s dynamic atmosphere, especially placed in context
of the imminent arrival of the New Horizons spacecraft.
---------------------------------------------------------
Title: Venus' thermospheric temperature field using a refraction
model at terminator : comparison with 2012 transit observations
using SDO/HMI, VEx/SPICAV/SOIR and NSO/DST/FIRS
Authors: Widemann, Thomas; Jaeggli, Sarah; Reardon, Kevin; Tanga,
Paolo; Père, Christophe; Pasachoff, Jay M.; Vandaele, Ann Carine;
Wilquet, Valerie; Mahieux, Arnaud; Wilson, Colin
2014DPS....4630206W Altcode:
The transit of Venus in June 2012 provided a unique case study of the
Venus' atmosphere transiting in front of the Sun, while at the same time
ESA's Venus Express orbiter observed the evening terminator at solar
ingress and solar egress.We report on mesospheric temperature at Venus'
morning terminator using SDO/HMI aureole photometry and comparison with
Venus Express. Close to ingress and egress phases, we have shown that
the aureole photometry reflects the local density scale height and the
altitude of the refracting layer (Tanga et al. 2012). The lightcurve of
each spatially resolved aureole element is fit to a two-parameter model
to constrain the meridional temperature gradient at terminator. Our
measurements are in agreement with the VEx/SOIR temperatures obtained
during orbit 2238 at evening terminator during solar ingress (46.75N -
LST = 6.075PM) and solar egress (31.30N - LST = 6.047PM) captured from
the Venus Express orbiter at the time Venus transited the Sun.We also
performed spectroscopy and polarimetry during the transit of Venus
focusing on extracting signatures of CO2 absorption. Observations were
taken during the first half of the transit using the Facility InfraRed
Spectropolarimeter (FIRS) on the Dunn Solar Telescope (DST). Although
the predicted CO2 transmission spectrum of Venus was not particularly
strong at 1565 nm, this region of the H-band often used in magnetic
field studies of the Sun's photosphere provides a particularly flat
solar continuum with few atmospheric lines. Sun-subtracted Venus limb
observations show intensity distribution of vibrational CO2 bands 221
2v+2v2+v3 at 1.571μm and 141 v1+4v2+v3 at 1.606μm.
---------------------------------------------------------
Title: Recreating Galileo's 1609 Discovery of Lunar Mountains
Authors: Pasachoff, Jay M.; Needham, Paul S.; Wright, Ernest T.;
Gingerich, Owen
2014DPS....4610606P Altcode:
The question of exactly which lunar features persuaded Galileo that
there were mountains on the moon has not yet been definitively answered;
Galileo was famously more interested in the concepts rather than the
topographic mapping in his drawings and the eventual engravings. Since
the pioneering work of Ewen Whitaker on trying to identify which
specific lunar-terminator features were those that Galileo identified
as mountains on the moon in his 1609 observations reported in his
Sidereus Nuncius (Venice, 1610), and since the important work on the
sequence of Galileo's observations by Owen Gingerich (see "The Mystery
of the Missing 2" in Galilaeana IX, 2010, in which he concludes that
"the Florentine bifolium sheet [with Galileo's watercolor images] is
Galileo's source for the reworked lunar diagrams in Sidereus Nuncius"),
there have been advances in lunar topographical measurements that
should advance the discussion. In particular, one of us (E.T.W.) at the
Scientific Visualization Studio of NASA's Goddard Space Flight Center
has used laser-topography from NASA's Lunar Reconnaissance Orbiter
to recreate what Galileo would have seen over a sequence of dates in
late November and early December 1609, and provided animations both
at native resolution and at the degraded resolution that Galileo would
have observed with his telescope. The Japanese Kaguya spacecraft also
provides modern laser-mapped topographical maps.
---------------------------------------------------------
Title: Atmospheric state of Pluto from the 31 July 2014 stellar
occultation
Authors: Person, Michael J.; Bosh, Amanda S.; Zuluaga, Carlos A.;
Kosiarek, Molly; Osip, David J.; Levine, Stephen E.; Pasachoff,
Jay M.; Schiff, Adam R.; Seegar, Christina H.; Babcock, Bryce A.;
Gulbis, Amanda A.; Rojo, Patricio
2014DPS....4641909P Altcode:
On 31 July 2014 (UT), while observing a potential Pluto occultation
(m=12, unfortunately obscured by clouds), we imaged a fortuitous
occultation by Pluto of a small companion star (m=15) several minutes
before the main event (and before the clouds came in) with the 6.5-m
Clay telescope at Magellan. The main star’s resulting light curve
(essentially flat until the weather intervened) was one of the highest
signal-to-noise light curves yet obtained from a Pluto occultation
observation. It will be analyzed for possible signatures of dust in the
Pluto system (see Levine et al., this meeting). Given the lower signal
to noise ratio provided by the secondary star, careful calibration is
needed to analyze the atmospheric occultation itself. Several other
attempts at observing Pluto occultations in July 2014 were unfortunately
clouded out (see Levine et al., Pasachoff et al., this meeting).Using
precise astrometry obtained with the 2.5-m DuPont telescope and the
4.3-m Discovery Channel telescope before and after the event, while
Pluto and the stars were well-separated, we are able to constrain
the closest approach distance of the secondary star occultation
event. Using the photometry from these same images, we are also able
to characterize the relative brightness of both stars in relation to
Pluto (taking care to account for the light from Charon as well). With
these two constraints we can analyze the atmospheric signature of the
occultation, and provide a current (July 2014) estimate of Pluto’s
changing atmospheric diameter. Initial results indicate no large
changes in the atmospheric scale height; complete results from the final
analysis will be presented with this work.This work was supported in
part by NASA Planetary Astronomy grants to MIT (NNX10AB27G) and Williams
College (NNX12AJ29G), as well as grants from USRA (#8500-98-003) and
Ames Research (#NAS2-97-01) to Lowell Observatory. P.R. acknowledges
support from FONDECYT through grant 1120299.
---------------------------------------------------------
Title: The H-R Diagram's 100th Anniversary
Authors: Pasachoff, Jay M.
2014S&T...127f..32P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Howard Russell Butler's Oil Paintings of Solar Eclipses
and Prominences
Authors: Pasachoff, Jay M.; Olson, Roberta J. M.
2014AAS...22420306P Altcode:
Howard Russell Butler (1856-1934) was invited to join the US Naval
Observatory expedition to the total solar eclipse of 1918 because of
his ability to paint astronomical phenomena based on quickly-made
notes about spatial and color details. His giant triptych of the
total eclipses of 1918, 1923, and 1925 was proposed for a never-built
astronomical center at the American Museum of Natural History and
wound up at their Hayden Planetarium when it was constructed in the
mid-1930s. Half-size versions are installed at the Fels Planetarium
at the Franklin Institute in Philadelphia and at the Firestone Library
of Princeton University, whose newly conserved canvases were recently
hung; the Buffalo Museum of Science has another half-size version in
storage. We discuss not only the eclipse triptychs but also the series
of large oil paintings he made of solar prominences (in storage at the
American Museum of Natural History) and of his 1932-eclipse and other
relevant works.JMP was supported for this work in part by Division
III Discretionary Funds and the Brandi Fund of Williams College. His
current eclipse research is supported by grants AGS-1047726 from the
Solar Research Program of the Atmospheric and Geospace Sciences Division
of NSF and 9327-13 from the Committee for Research and Exploration of
the National Geographic Society.
---------------------------------------------------------
Title: Imaging and Spectra of the Chromosphere and Corona at the
2013 Total Eclipse in Gabon
Authors: Pasachoff, Jay M.; Davis, Allen B.; Demianski, Marek;
Rusin, Vojtech; Saniga, Metod; Seaton, Daniel B; Gaintatzis, Pavlos;
Voulgaris, Aristeidis; Lucas, Robert; Edwards, Zophia; Zeiler, Michael;
Kentrianakis, Michael
2014AAS...22432316P Altcode:
We successfully observed the 3 November 2013 eclipse's 59 s of totality
in clear sky from the centerline of totality where it exited La Lope
National Park in Gabon, close to the maximum totality available
on land. Our wide-field imaging showed two CMEs and an erupting
prominence. We compare our images with those obtained elsewhere in
totality to assess motion and dynamics. Our imaging observations are
also compared with near-simultaneous observations from SDO/AIA, SDO/HMI,
Hinode/XRT, SOHO/LASCO, SOHO/EIT, PROBA2/SWAP, and STEREO/SECCHI. We
also have flash and coronal spectra, which continue to show overall
warming of the corona in 2012 and 2013 through studies we have made over
the solar cycle that include the ratio of intensities of the coronal
red (Fe X 637.4 nm) and green (Fe XIV 530.3 nm) forbidden lines.The
Williams College 2013 total-eclipse expedition was supported in part
by grant 9327-13 from the Committee for Research and Exploration
of the National Geographic Society. Our continued work on the 2012
eclipse results is supported in part by grant AGS-1047726 from Solar
Terrestrial Research/NSF AGS.
---------------------------------------------------------
Title: Book Review: A History of Telescopes
Authors: Pasachoff, Jay M.
2014JHA....45..256P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Venus' thermospheric temperature field using a refraction
model at terminator : comparison with 2012 transit observations
using SDO/HMI and NSO/DST/FIRS
Authors: Widemann, Thomas; Tanga, Paolo; Père, Christophe; Jaeggli,
Sarah; Reardon, Kevin; Pasachoff, Jay M.
2014EGUGA..1612916W Altcode:
The transit of Venus in June 2012 provided a unique case study of an
Earth-size planet's atmosphere transiting in front of its parent star
at 0.7AU, while at the same time ESA's Venus Express orbiter observed
the evening terminator at solar ingress and solar egress. We report
on mesospheric temperature at Venus' morning terminator using SDO/HMI
aureole photometry and comparison with Venus Express. Close to ingress
and egress phases, we have shown that the aureole photometry reflects
the local density scale height and the altitude of the refracting layer
(Tanga et al. 2012). The lightcurve of each spatial resolution element
of the aureole is compared to a two-parameter model to constrain the
meridional temperature gradient along the terminator. Our measurements
are in agreement with the VEx/SOIR temperatures obtained during
orbit 2238 at evening terminator during solar ingress (46.75N - LST
= 6.075PM) and solar egress (31.30N - LST = 6.047PM) captured from
the Venus Express orbiter at the time Venus transited the Sun for
Earth-based observers. We also performed spectroscopy and polarimetry
during the transit of Venus focusing on extracting signatures of
CO2 absorption. Observations were taken during the first half of the
transit using the Facility InfraRed Spectropolarimeter on the Dunn
Solar Telescope. Although the predicted CO2 transmission spectrum
of Venus was not particularly strong at 1565 nm, this region of the
H-band often used in magnetic field studies of the Sun's photosphere
provides a particularly flat solar continuum with few atmospheric and
molecular lines. Sun-subtracted Venus limb observations show intensity
distribution of vibrational CO2 bands 221 2v + 2ν2 + ν3 at 1.571um and
141 ν1 + 4ν2 + ν3 at 1.606um. Data independently allow to constrain
temperature as well as cross-terminator thermospheric winds.
---------------------------------------------------------
Title: Astronomy: Art of the eclipse
Authors: Pasachoff, Jay M.; Olson, Roberta J. M.
2014Natur.508..314P Altcode:
As the next solar eclipse approaches, Jay M. Pasachoff and Roberta
J. M. Olson ponder how artists from the early Renaissance onwards have
interpreted the phenomenon.
---------------------------------------------------------
Title: Nearest Star
Authors: Golub, Leon; Pasachoff, Jay M.
2014nest.book.....G Altcode:
Preface; Acknowledgments; 1. The Sun; 2. The once and future Sun;
3. What we see: the solar disk; 4. What we don't see; 5. Eclipses;
6. Space missions; 7. Between fire and ice; 8. Space weather;
Bibliography; Glossary; Index.
---------------------------------------------------------
Title: Solar Activity and Motions in the Solar Chromosphere and
Corona at the 2012 and 2013 Total and Annular Eclipses in the U.S.,
Australia, and Africa
Authors: Pasachoff, Jay M.; Babcock, B. A.; Davis, A. B.; Demianski,
M.; Lucas, R.; Lu, M.; Dantowitz, R.; Rusin, V.; Saniga, M.; Seaton,
D. B.; Gaintatzis, P.; Voulgaris, A.; Seiradakis, J. H.; Gary, D. E.;
Shaik, S. B.
2014AAS...22311801P Altcode:
Our studies of the solar chromosphere and corona at the 2012 and
2013 eclipses shortly after cycle maximum 24 (2011/2012) of solar
activity (see: http://www.swpc.noaa.gov/SolarCycle/) involved radio
observations of the 2012 annular eclipse with the Jansky Very Large
Array, optical observations of the 2012 total eclipse from Australia,
optical observations of the 2013 annular eclipse from Tennant Creek,
Australia, and the 3 November 2013 total solar eclipse from Gabon. Our
observations are coordinated with those from solar spacecraft: Solar
Dynamics Observatory AIA and HMI, Hinode XRT and SOT, SOHO LASCO and
EIT, PROBA2 SWAP, and STEREO SECCHI. Our 2012 totality observations
include a CME whose motion was observed with a 37-minute interval. We
include first results from the expedition to Gabon for the 3 November
2013 eclipse, a summary of eclipse results from along the path of
totality across Africa, and a summary of the concomitant spacecraft
observations. The Williams College 2012 expeditions were supported in
part by NSF grant AGS-1047726 from Solar Terrestrial Research/NSF AGS,
and by the Rob Spring Fund and Science Center funds at Williams. The
JVLA is supported by the NSF. The Williams College 2013 total-eclipse
expedition was supported in part by grant 9327-13 from the Committee
for Research and Exploration of the National Geographic Society. ML was
also supported in part by a Grant-In-Aid of Research from the National
Academy of Sciences, administered by Sigma Xi, The Scientific Research
Society (Grant ID: G20120315159311). VR and MS acknowledge support
for 2012 from projects VEGA 2/0003/13 and NGS-3139-12 of the National
Geographic Society. We are grateful to K. Shiota (Japan) for kindly
providing us with some of his 2012 eclipse coronal images. We thank
Alec Engell (Montana State U) for assistance on site, and Terry Cuttle
(Queensland Amateur Astronomers) for help with site arrangements. We
thank Aram Friedman (Ansible Technologies), Michael Kentrianakis,
and Nicholas Weber (Dexter Southfield School) for collaboration on
imaging at the Australian total eclipse.
---------------------------------------------------------
Title: Pond, John
Authors: Pasachoff, Naomi; Pasachoff, Jay M.
2014bea..book.1745P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Observations of the Black-Drop Effect at the 2012 Transit
of Venus
Authors: Rogoszinski, Zeeve; Pasachoff, J. M.; Babcock, B. A.;
Schneider, G.; Reardon, K. P.
2014AAS...22324716R Altcode:
We observed the 2012 transit of Venus from several locations,
including the Mees Solar Observatory of the University of Hawaii on
Maui; the Dunn Solar Telescope at the Sacramento Peak Observatory of
the National Solar Observatory in Sunspot, NM; and the Big Bear Solar
Observatory of the New Jersey Institute of Technology in California. Our
observations, mainly directed at the study of Venus's atmosphere, also
included high-resolution views of the black-drop effect. Historically,
the black-drop effect proved to be a daunting anomaly for measuring
the path length of Venus across the Sun’s surface with sufficient
time accuracy to allow satisfactory measurement of the astronomical
unit. Therefore, this phenomenon set back the accurate calculations
for centuries of the size and scale of the solar system. In this
paper, we discuss data taken with the New Solar Telescope at the Big
Bear Observatory and with the IBIS on the Dunn Solar Telescope. We
show the evolution of isophotes as a function of time to demonstrate
various limb effects during second and third contacts. Schneider,
Pasachoff, and Golub (Icarus 168. 249-256, 2004) have shown that the
black-drop effect as seen in a transit of Mercury resulted from both the
point-spread function of the telescope and the extreme limb-darkening
effect at the region of the solar limb where the black-drop effect is
demonstrated, and the current paper extends the analysis to the recent
transit of Venus. As they showed, and as is verified here, Venus's
atmosphere plays no role in the black-drop effect. ZR (Vassar '14)
was a Keck Northeast Astronomy Consortium Summer Fellow at Williams
College, supported by an NSF/REU grant to the Keck Northeast Astronomy
Consortium. This research used the following tools: IDL/IDP3, ImageJ,
and DS9. For obtaining the data at the Big Bear Solar Observatory,
we thank Vasyl Yurchyshyn. Special thanks goes to Dr. Steven Souza
for his support. The 2012 observations were obtained with a grant from
the Committee for Research and Exploration of the National Geographic
Society.
---------------------------------------------------------
Title: Observation and Analysis of a Single-Chord Stellar Occultation
by Kuiper Belt Object (50000) Quaoar
Authors: Davis, Allen B.; Pasachoff, J. M.; Babcock, B. A.; Person,
M. J.; Zuluaga, C. A.; Bosh, A. S.; Levine, S.; Naranjo, O. A.; Navas,
G. R.; Gulbis, A.; Winters, J. G.; Bianco, F.
2014AAS...22324708D Altcode:
The Williams-MIT collaboration (www.stellaroccultations.info)
predicted and observed a stellar occultation of 2UCAC 26260847 (mag
14.35) by KBO 50000 Quaoar (mag 18.9) on 8/9 July 2013. Observations
were attempted from a total of five sites in Chile, Venezuela, and
Massachusetts. Only one site, Llano del Hato National Astronomical
Observatory in Venezuela, had a positive detection of the occultation,
giving us a single chord on Quaoar. All other sites were cloudy. The
light curve from the 8/9 July 2013 event has been analyzed with the
assumption that Quaoar is ellipsoidal or spherical, placing bounds
on some of Quaoar’s properties: diameter (> 1138 ± 25 km),
density (< 1.82 ± 0.28 g cm<SUB>-3</SUB>), and albedo (< 0.14 ±
0.10). An independent prediction of the occultation’s shadow path by
Fraser, Gwyn, et al. (2013) suggests that the chord is near-equatorial,
which means that our bounds on Quaoar’s properties are closer to
estimates. We will compare our result with that of the 11 February
2011 single-chord occultation detected by Sallum et al. (2011) and
Person et al. (2011). A subsequent attempt to observe a second Quaoar
occultation, that of 12/13 July 2013 in South Africa, failed because
of cloudy weather. This work was supported in part by NASA Planetary
Astronomy grants NNX08AO50G and NNH11ZDA001N to Williams College,
NNX10AB27G to MIT, and USRA grant #8500-98-003 to Lowell Observatory. We
thank Steven P. Souza at Williams, and other collaborators in planning
and carrying out the various observations: including Libardo Zerpa,
Joresly Villarreal, Richard Rojas, and Jorge Moreno at Llano del Hato,
and Patricio Rojo and Matias Jones at Cerro Calan/U. Chile.
---------------------------------------------------------
Title: Messier, Copernicus, Flamsteed: The SAF Rare-Book Collection
in Paris
Authors: Pasachoff, Jay M.
2014AAS...22310707P Altcode:
The historic books belonging to the Société Astronomique de France,
founded by Camille Flammarion in 1887, are located partly in Paris
and partly at the Flammarion site in Juvisy, a Paris suburb. Their
holdings include first editions of Copernicus's De Revolutionibus and
of Flamsteed's star atlas, as well as Messier's own copy of his 1783
and 1784 papers with his handwritten comments and additions. I will
describe the fruitless search for a Bevis atlas and the circumstances
that led me to inspect these treasures. I thank David Valls-Gabaud
and Philippe Morel of the Société Astronomique de France for their
hospitality in Paris, Jean-Claude Pecker, and Owen Gingerich for his
prior work on Messier's catalogue.
---------------------------------------------------------
Title: Morley, Edward Williams
Authors: Pasachoff, Naomi; Pasachoff, Jay M.
2014bea..book.1524P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Russell, Henry Norris
Authors: Pasachoff, Naomi; Pasachoff, Jay M.
2014bea..book.1881P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Hypatia
Authors: Pasachoff, Naomi; Pasachoff, Jay M.
2014bea..book.1014P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The 2011 June 23 Stellar Occultation by Pluto: Airborne and
Ground Observations
Authors: Person, M. J.; Dunham, E. W.; Bosh, A. S.; Levine, S. E.;
Gulbis, A. A. S.; Zangari, A. M.; Zuluaga, C. A.; Pasachoff, J. M.;
Babcock, B. A.; Pandey, S.; Amrhein, D.; Sallum, S.; Tholen, D. J.;
Collins, P.; Bida, T.; Taylor, B.; Bright, L.; Wolf, J.; Meyer, A.;
Pfueller, E.; Wiedemann, M.; Roeser, H. -P.; Lucas, R.; Kakkala,
M.; Ciotti, J.; Plunkett, S.; Hiraoka, N.; Best, W.; Pilger, E. J.;
Micheli, M.; Springmann, A.; Hicks, M.; Thackeray, B.; Emery, J. P.;
Tilleman, T.; Harris, H.; Sheppard, S.; Rapoport, S.; Ritchie, I.;
Pearson, M.; Mattingly, A.; Brimacombe, J.; Gault, D.; Jones, R.;
Nolthenius, R.; Broughton, J.; Barry, T.
2013AJ....146...83P Altcode:
On 2011 June 23, stellar occultations by both Pluto (this work) and
Charon (future analysis) were observed from numerous ground stations
as well as the Stratospheric Observatory for Infrared Astronomy
(SOFIA). This first airborne occultation observation since 1995 with
the Kuiper Airborne Observatory resulted in the best occultation
chords recorded for the event, in three visible wavelength bands. The
data obtained from SOFIA are combined with chords obtained from the
ground at the IRTF, the U.S. Naval Observatory Flagstaff Station,
and Leeward Community College to give the detailed state of the
Pluto-Charon system at the time of the event with a focus on Pluto's
atmosphere. The data show a return to the distinct upper and lower
atmospheric regions with a knee or kink in the light curve separating
them as was observed in 1988, rather than the smoothly transitioning
bowl-shaped light curves of recent years. The upper atmosphere is
analyzed by fitting a model to all of the light curves, resulting in
a half-light radius of 1288 ± 1 km. The lower atmosphere is analyzed
using two different methods to provide results under the differing
assumptions of particulate haze and a strong thermal gradient as
causes for the lower atmospheric diminution of flux. These results
are compared with those from past occultations to provide a picture
of Pluto's evolving atmosphere. Regardless of which lower atmospheric
structure is assumed, results indicate that this part of the atmosphere
evolves on short timescales with results changing the light curve
structures between 1988 and 2006, and then reverting these changes
in 2011 though at significantly higher pressures. Throughout these
changes, the upper atmosphere remains remarkably stable in structure,
again except for the overall pressure changes. No evidence of onset
of atmospheric collapse predicted by frost migration models is seen,
and the atmosphere appears to be remaining at a stable pressure level,
suggesting it should persist at this full level through New Horizon's
flyby in 2015.
---------------------------------------------------------
Title: Recent KBO (Pluto/Charon and beyond, including Quaoar)
Occultation Observations by the Williams College Team as part of
the Williams-MIT Collaboration
Authors: Pasachoff, Jay M.; Babcock, B. A.; Davis, A. B.; Pandey, S.;
Lu, M.; Rogosinski, Z.; Person, M. J.; Bosh, A. S.; Zangari, A. M.;
Zuluaga, C. A.; Gulbis, A. S.; Naranjo, O.; Navas, G.; Zerpa, L.;
Villarreal, J.; Rojo, P.; Förster, F.; Servajean, E.
2013DPS....4531001P Altcode:
The Williams College-MIT collaboration has observed numerous
occultations of stars by Pluto/Charon and other Kuiper-belt objects
(www.stellaroccultations.info), since its establishment three decades
ago with an attempted discovery of Neptune's rings in 1983. In this
paper, we describe several recent occultation observations, both
successful and (for reasons of path uncertainties and/or weather)
unsuccessful. Light curves made or arranged by Williams College faculty
and students were used together with light curves by MIT colleagues and
others to study Pluto's atmosphere and Charon's size, to discover one of
the highest-known solar-system albedos (KBO 55636), and to attempt to
study 1000-km-diameter Quaoar. Observations discussed include light
curves for KBO 55636 on 9 October 2009 from Hawaii; Pluto on 3/4
July 2010 from Chile, 22 May 2011 from Williamstown, Massachusetts,
23 June 2011 from Hawaii (in support of SOFIA observations of Pluto's
atmosphere, discussed in an article in press in AJ and of the pair of
Pluto/Charon occultations of the same star), and 4 May 2013 (Bosh et
al., this conference) and 15 July 2013 from Williamstown; Charon on 15
June 2013 from Williamstown; Quaoar from a picket fence ranging from
Chile through Venezuela (with a detection there) to Massachusetts on
July 8/9 and in South Africa on 12 July 2013. This work was supported
in part by NASA Planetary Astronomy grants NNX08AO50G and NNH11ZDA001N
to Williams College, NNX10AB27G to MIT, and USRA grant #8500-98-003 to
Lowell Observatory. We thank Steven P. Souza at Williams; Steven Levine
at Lowell Obs.; Jennifer G. Winters (GSU) in Chile; Richard Rojas/Jorge
Moreno in Venezuela; Scott Sheppard; Federica Bianco; David Osip;
and others. ZR (Vassar '14) was a Keck Northeast Astronomy Consortium
Summer Fellow at Williams College, supported by an NSF/REU grant to the
Keck Northeast Astronomy Consortium. ES: partial support from Programa
Nacional de Becas de Postgrado (CONICYT Grant 21110496). FF: support
from FONDECYT through grant 3110042 and by the Millennium Center for
Supernova Science, grant P10-064-F. funded by Programa Bicentenario de
Ciencia y Tecnología de CONICYT and Programa Iniciativa Científíca
Milenio de MIDEPLAN.
---------------------------------------------------------
Title: The Planetary and Eclipse Oil Paintings of Howard Russell
Butler
Authors: Pasachoff, Jay M.; Olson, R. M.
2013DPS....4510803P Altcode:
The physics-trained artist Howard Russell Butler (1856-1934) has
inspired many astronomy students through his planetary and eclipse
paintings that were long displayed at the Hayden Planetarium in New
York, the Fels Planetarium at the Franklin Institute in Philadelphia,
and the Buffalo Museum of Science. We discuss not only the eclipse
triptychs (1918, 1923, and 1925) at each of those institutions but
also his paintings of Mars as seen from Phobos and from Deimos (with
landscapes of those moons in the foreground depicted in additional
oils hung at Princeton University) and the Earth from our Moon. We also
describe his involvement with astronomy and his unique methodology that
allowed him to surpass the effects then obtainable with photography,
as well as his inclusion in a U.S. Naval Observatory eclipse expedition
in 1918, as well as his auroral, solar-prominence, and 1932-eclipse
paintings.
---------------------------------------------------------
Title: Characterization of a transiting exo-Venus : lessons from
the 2012 Transit
Authors: Widemann, Thomas; Jaeggli, S. A.; Reardon, K. P.; Tanga,
P.; Pasachoff, J. M.; Schneider, G.
2013DPS....4511811W Altcode:
The transit of Venus in June 2012 provided a unique chance to
view a well studied planetary atmosphere as we might see that of a
transiting exoplanet, through scattered and refracted illumination
of its parent star. We report on mesospheric temperature at Venus'
morning terminator using SDO/HMI aureole photometry and comparison with
Venus Express. Close to ingress and egress phases, we have shown that
the aureole photometry reflects the local density scale height and the
altitude of the refracting layer (Tanga et al. 2012). The lightcurve
of each spatial resolution element of the aureole is compared to a
two-parameter model to constrain the meridional temperature gradient
along the terminator. Our measurements are in agreement with the
VEx/SOIR temperatures obtained during orbit 2238 at evening terminator
during solar ingress (46.75N - LST = 6.075PM) and solar egress (31.30N -
LST = 6.047PM) as seen from the orbiter. Imaging data using IBIS/ROSA on
the Dunn Solar Telescope in the G-band (430 nm) are also presented. We
also performed spectroscopy and polarimetry during the transit of Venus
focusing on extracting signatures of CO2 absorption. Observations were
taken during the first half of the transit using the Facility InfraRed
Spectropolarimeter on the Dunn Solar Telescope. Although the predicted
CO2 transmission spectrum of Venus was not particularly strong at 1565
nm, this region of the H-band often used in magnetic field studies of
the Sun's photosphere provides a particularly flat solar continuum
with few atmospheric and molecular lines. Sun-subtracted Venus limb
observations show intensity distribution of vibro-rotational CO2 band
221 2ν + 2ν2 + ν3 at 1.571μm allowing for an additional constraint
on Venus' thermospheric temperature.
---------------------------------------------------------
Title: The State of Pluto's Atmosphere in 2012-2013
Authors: Bosh, Amanda S.; Person, M. J.; Levine, S. E.; Zuluaga, C. A.;
Zangari, A. M.; Ruprecht, J. D.; Bowens-Rubin, R.; Brothers, T. C.;
Berry, K. L.; Babcock, B. A.; Pasachoff, J. M.; Rojo, P.; Servajean,
E.; Förster, F.; Naranjo, O. A.; Taylor, B. W.; Dunham, E. W.; Oswalt,
T.; Batcheldor, D.; Murison, M.; Tilleman, T.; Harris, H. C.; Bright,
L. P.; Schaefer, G.; Sallum, S.; Midkiff, A. H.; Mailhot, E. A.;
Miller, C.; Morris, D.; Wodaski, R.; Bell, D.; Bird, P.; Fey, D.;
Geisert, E.; Hastings, D.; Mizusawa, T.; Solenski, P.; Watson, B.
2013DPS....4540401B Altcode:
We observed two stellar occultations on UT 4 May 2013 and UT 9 September
2012, with the aim of measuring Pluto's atmospheric parameters. Both
of these events were a world-wide collaboration of many observers,
and both occurred within one month of Pluto's stationary point. For
the May 2013 occultation of an R=14.0 star, observations were
attempted from several sites in Chile, Venezuela, Arizona, and
Massachusetts. Positive detections were made from the DuPont 2.5-m at
Las Campanas, the SMARTS 1-m at Cerro Tololo, and the 0.45-m telescope
at Cerro Calan, all in Chile. For the September 2012 occultation of an
R=15.2 star, observations were attempted from many sites along the east
coast of the U.S., and in Arizona, New Mexico, and Texas. Successful
atmosphere occultation light curves were obtained from the MONET 1.2-m
at the McDonald Observatory and the FIT Ortega 0.8-m in Melbourne,
Florida. From these data, we find that Pluto's atmosphere has maintained
the basic parameters of the 2011 measurement (Person, et al., in press)
with some small but significant structural changes. The atmospheric
temperature and pressure are similar to 2011 values, while the "knee"
structure at half-light has continued to evolve and has been further
modified since 2011. This light curve evolution maps to changes in the
temperature structure and/or haze distribution in the lower atmosphere
approximately 1-2 scale heights above the surface. We will present
these recent data and discuss their implications for atmospheric
change on Pluto as well as extrapolations toward the New Horizons
encounter in 2015. This work was supported in part by NASA Planetary
Astronomy grants to MIT (NNX10AB27G) and Williams College (NNX08AO50G,
NNH11ZDA001N), as well as grants from USRA (#8500-98-003) and Ames
Research (#NAS2-97-01) to Lowell Observatory. The observations made
at FIT were partially supported by the James and Sara Ortega Endowment.
---------------------------------------------------------
Title: The Cosmos
Authors: Pasachoff, Jay M.; Filippenko, Alex
2013cosm.book.....P Altcode:
Preface; About the authors; 1. A grand tour of the heavens; 2. Light,
matter and energy: powering the Universe; 3. Light and telescopes:
extending our senses; 4. Observing the stars and planets: clockwork of
the Universe; 5. Gravitation and motion: the early history of astronomy;
6. The terrestrial planets: Earth, Moon, and their relatives; 7. The
Jovian planets: windswept giants; 8. Pluto, comets, and space debris;
9. Our Solar System and others; 10. Our star: the Sun; 11. Stars:
distant suns; 12. How the stars shine: cosmic furnaces; 13. The
death of stars: recycling; 14. Black holes: the end of space and time;
15. The Milky Way: our home in the Universe; 16. A Universe of galaxies;
17. Quasars and active galaxies; 18. Cosmology: the birth and life of
the cosmos; 19. In the beginning; 20. Life in the Universe; Epilogue;
Appendices; Selected readings; Glossary; Index.
---------------------------------------------------------
Title: Letters to the Editor
Authors: Pasachoff, J. M.
2013JRASC.107..179P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: 1565 nm Observations of the transit of Venus, Proxy for a
Transiting Exoplanet
Authors: Jaeggli, Sarah A.; Reardon, K. P.; Pasachoff, J. M.;
Schneider, G.; Widemann, T.; Tanga, P.
2013SPD....44..150J Altcode:
The transit of Venus in June 2012 provided a unique chance to view its
atmosphere as we might see that of a transiting Cytherean exoplanet,
through scattered and refracted illumination from its parent star. We
performed spectroscopy and polarimetry during the transit of Venus
focusing on extracting signatures of CO2 absorption of Venus from the
solar spectrum. Although the predicted CO2 transmission spectrum of
Venus was not particularly strong at 1565 nm, this region of the H-band
often used in magnetic-field studies of the Sun's photosphere provides
a particularly flat solar continuum with few atmospheric and molecular
lines. Observations of Venus were taken throughout first contact
and on the solar disk using the Facility InfraRed Spectropolarimeter
on the Dunn Solar Telescope at the National Solar Observatory. The
transit also provided a unique opportunity to investigate instrumental
effects. In this poster we discuss initial results from the transit,
including estimates for an exoplanet detection of this kind, preliminary
comparison with atmospheric models, and the stray light properties
of the instrument. This work was performed in collaboration with the
Williams College Venus transit expedition, which was sponsored by Natl
Geog/Comm for Research and Exploration.
---------------------------------------------------------
Title: The 2012 Total Eclipse Expeditions in Queensland
Authors: Pasachoff, Jay M.; Babcock, B. A.; Lu, M.; Dantowitz, R.;
Lucas, R.; Seiradakis, J. H.; Voulgaris, A.; Gaintatzis, P.; Steele,
A.; Sterling, A. C.; Rusin, V.; Saniga, M.
2013SPD....44...51P Altcode:
A total eclipse swept across Queensland and other sites in northeastern
Australia on the early morning of 14 November 2012, local time. We
mounted equipment to observe coronal images and spectra during the
approximately 2 minutes of totality, the former for comparison with
spacecraft images and to fill in the doughnut of imaging not well
covered with space coronagraphs. Matching weather statistics, viewing
was spotty, and our best observations were from a last-minute inland
site on the Tablelands, with some observations from a helicopter at 9000
feet altitude over our original viewing site at Miallo. Only glimpses of
the corona were visible at our Port Douglas and Trinity Beach, Cairns,
locations, with totality obscured from our sites at Newell and Miallo,
though some holes in the clouds provided coronal views from Palm Cove
and elsewhere along the coast. Preliminary analysis of the spectra
again shows Fe XIV stronger than Fe X, as in 2010 but not earlier,
a sign of solar maximum, as was the coronal shape. An intriguing CME
is discernible in the SE. Acknowledgments: We thank Terry Cuttle, Aram
Friedman, Michael Kentrianakis, and Nicholas Weber for assistance and
collaboration in Australia and Wendy Carlos for image processing. Our
expedition was supported in part by NSF grant AGS-1047726 from Solar
Terrestrial Research of the Atmospheric and Geospace Sciences Division,
and by the Rob Spring Fund and Science Center funds at Williams
College. ML was also supported in part by a Grant-In-Aid of Research
from the National Academy of Sciences, administered by Sigma Xi, The
Scientific Research Society (Grant ID: G20120315159311). VR and MS
acknowledge support from projects VEGA 2/0003/13 and NGS-3139-12 of
the National Geographic Society. We are grateful to K. Shiota (Japan)
for kindly providing us with some of his 2012 eclipse coronal images.
---------------------------------------------------------
Title: Observations and Modeling of Solar Coronal Structures Using
High-Resolution Eclipse Images and Space-based Telescopes with Wide
Field of View
Authors: Lu, Muzhou; Pasachoff, J. M.; Su, Y.; Van Ballegooijen,
A. A.; Seaton, D. B.; West, M.
2013SPD....44...25L Altcode:
We present a comparison of the solar corona observed during the total
solar eclipses on 2010 July 11 and on 2012 November 13. The white
light images were taken at Easter Island in 2010 and at Northeast
Queensland, Australia, in 2012; while the concurrent EUV images were
take with SDO/AIA and PROBA2/SWAP. The 2010 eclipse was observed at
the beginning of Sunspot Cycle 24 [1], which peaked near our 2012
observation. We compare a plethora of corona features in the white
light images and reveal some interesting differences in the enhanced EUV
images taken by SDO/AIA and PROBA2/SWAP. We construct potential field
models using our newly refined Coronal Modeling System (CMS2) software
with line-of-sight photospheric magnetograms from SDO/HMI. The source
surface heights derived from detailed comparison between our models
and observations are compared to the standard source-surface model. We
also compare the dynamics of the two eclipse observations. Similar to
the 2010 eclipse, a CME was observed using temporally spaced eclipse
images. We address unresolved problems in the models and observations
with the hope of correcting them for future eclipse observations, such
as the 2017 total solar eclipse across the continental U.S. References
[1] Pasachoff, J. M., Rusin, V., Druckmüllerová, H., Saniga, M.,
Lu, M., Malamut, C., Seaton, D. B., Golub, L., Engell, A. J., Hill,
S. W., Lucas, R., 2011, ApJ, 734, 114
---------------------------------------------------------
Title: Transit Observations of Venus's Atmosphere in 2012 from
Terrestrial and Space Telescopes as Exoplanet Analogs
Authors: Pasachoff, Jay M.; Schneider, G.; Babcock, B. A.; Lu, M.;
Penn, M. J.; Jaeggli, S. A.; Galayda, E.; Reardon, K. P.; Widemann,
T.; Tanga, P.; Ehrenreich, D.; Vidal-Madjar, A.; Nicholson, P. D.;
Dantowitz, R.
2013AAS...22221701P Altcode:
We extensively observed the 8 June 2012 transit of Venus from several
sites on Earth; we provide this interim status report about this and
about two subsequent ToVs observed from space. From Haleakala Obs., we
observed the entire June transit over almost 7 h with a coronagraph of
the Venus Twilight Experiment B filter) and with a RED Epic camera to
compare with simultaneous data from ESA's Venus Express, to study the
Cytherean mesosphere; from Kitt Peak, we have near-IR spectropolarimetry
at 1.6 µm from the aureole and during the disk crossing that compare
well with carbon dioxide spectral models; from Sac Peak/IBIS we have
high-resolution imaging of the Cytherean aureole for 22 min, starting
even before 1st contact; from Big Bear, we have high-resolution imaging
of Venus's atmosphere and the black-drop effect through 2nd contact;
and we had 8 other coronagraphs around the world. For the Sept 21 ToV
as seen from Jupiter, we had 14 orbits of HST to use Jupiter's clouds
as a reflecting surface to search for an 0.01% diminution in light and a
differential drop that would result from Venus's atmosphere by observing
in both IR/UV, for which we have 170 HST exposures. As of this writing,
preliminary data reduction indicates that variations in Jovian clouds
and the two periods of Jupiter's rotation will be too great to allow
extraction of the transit signal. For the December 20 ToV as seen from
Saturn, we had 22 hours of observing time with VIMS on Cassini, for
which we are looking for a signal of the 10-hr transit in total solar
irradiance and of Venus's atmosphere in IR as an exoplanet-transit
analog. Our Maui & Sac Peak expedition was sponsored by National
Geographic Society's Committee for Research and Exploration; HST data
reduction by NASA: HST-GO-13067. Some of the funds for the carbon
dioxide filter for Sac Peak provided by NASA through AAS's Small
Research Grant Program. We thank Rob Ratkowski of Haleakala Amateur
Astronomers; Rob Lucas, Aram Friedman, Eric Pilger, Stan Truitt,
and Steve Bisque/Software Bisque for Haleakala support/operations;
Vasyl Yurchyshyn and Joseph Gangestad '06 of The Aerospace Corp. at
Big Bear Solar Obs; LMSAL and Hinode science/operations team.
---------------------------------------------------------
Title: Standardizing the astronomical unit
Authors: Pasachoff, Jay M.
2013PhTea..51..260P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Pen & Pixel NGC 1055 and M77 / Comet Hergenrother /
Milky Way / IC 342 / November Eclipse / The Crab Nebula / Milky Way
with Trees
Authors: Hilborn, Lynn; Paquette, Andre; Brasch, Klaus; Pasachoff,
Jay; Hilborn, Lynn; Wilson, Dalton; Wiwchar, Sheila
2013JRASC.107...25H Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Three 2012 Transits of Venus: From Earth, Jupiter, and Saturn
Authors: Pasachoff, Jay M.; Schneider, G.; Babcock, B. A.; Lu, M.;
Edelman, E.; Reardon, K.; Widemann, T.; Tanga, P.; Dantowitz, R.;
Silverstone, M. D.; Ehrenreich, D.; Vidal-Madjar, A.; Nicholson,
P. D.; Willson, R. C.; Kopp, G. A.; Yurchyshyn, V. B.; Sterling,
A. C.; Scherrer, P. H.; Schou, J.; Golub, L.; McCauley, P.; Reeves, K.
2013AAS...22131506P Altcode:
We observed the 2012 June 6/5 transit seen from Earth (E/ToV),
simultaneously with Venus Express and several other spacecraft
not only to study the Cytherean atmosphere but also to provide an
exoplanet-transit analog. From Haleakala, the whole transit was visible
in coronal skies; among our instruments was one of the world-wide Venus
Twilight Experiment's nine coronagraphs. Venus's atmosphere became
visible before first contact. SacPeak/IBIS provided high-resolution
images at Hα/carbon-dioxide. Big Bear's NST also provided
high-resolution observations of the Cytherean atmosphere and black-drop
evolution. Our liaison with UH's Mees Solar Observatory scientists
provided magneto-optical imaging at calcium and potassium. Solar
Dynamics Observatory's AIA and HMI, and the Solar Optical Telescope
(SOT) and X-ray Telescope (XRT) on Hinode, and total-solar-irradiance
measurements with ACRIMSAT and SORCE/TIM, were used to observe the
event as an exoplanet-transit analog. On September 20, we imaged
Jupiter for 14 Hubble Space Telescope orbits, centered on a 10-hour
ToV visible from Jupiter (J/ToV), as an exoplanet-transit analog in
our own solar system, using Jupiter as an integrating sphere. Imaging
was good, although much work remains to determine if we can detect
the expected 0.01% solar irradiance decrease at Jupiter and the even
slighter differential effect between our violet and near-infrared
filters caused by Venus's atmosphere. We also give a first report on our
currently planned December 21 Cassini UVIS observations of a transit of
Venus from Saturn (S/ToV). Our E/ToV expedition was sponsored by the
Committee for Research and Exploration/National Geographic Society;
supplemented: NASA/AAS's Small Research Grant Program. We thank Rob
Ratkowski, Stan Truitt, Rob Lucas, Aram Friedman, and Eric Pilger
'82 at Haleakala, and Joseph Gangestad '06 at Big Bear for assistance,
and Lockheed Martin Solar and Astrophysics Lab and Hinode science and
operations teams for support for coordinated observations with NASA
satellites. Our J/ToV observations were based on observations made
with HST, operated by AURA, Inc., under NASA contract NAS 5-26555;
these observations are associated with program #13067.
---------------------------------------------------------
Title: A Major Discovery in Doubt
Authors: Pasachoff, Jay M.; Sheehan, William
2013S&T...125a..86P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Innovation in Astronomy Education
Authors: Pasachoff, Jay M.; Ros, Rosa M.; Pasachoff, Naomi
2013iae..book.....P Altcode:
Preface; Part I. General Strategies for Effective Teaching:
Introduction; 1. Main objectives of SpS2; 2. Learning astronomy
by doing astronomy; 3. Hands-on Universe-Europe; 4. Life on Earth
in the atmosphere of the Sun; 5. A model of teaching astronomy to
pre-service teachers; 6. How to teach, learn about, and enjoy astronomy;
7. Clickers: a new teaching tool of exceptional promise; 8. Educational
opportunities in pro-am collaboration; 9. Teaching history of astronomy
to second-year engineering students; 10. Teaching the evolution of
stellar and Milky Way concepts through the ages; 11. Educational efforts
of the International Astronomical Union; 12. Astronomy in culture;
13. Light pollution: a tool for astronomy education; 14. Astronomy by
distance learning; 15. Edible astronomy demonstrations; 16. Amateur
astronomers as public outreach partners; 17. Does the Sun rotate
around Earth or Earth rotate around the Sun?; 18. Using sounds and
sonifications for astronomy outreach; 19. Teaching astronomy and
the crisis in science education; 20. Astronomy for all as part of a
general education; Poster abstracts; Part II. Connecting Astronomy
with the Public: Introduction; 21. A status report from the Division
XII working group; 22. Outreach using media; 23. Astronomy podcasting;
24. IAU's communication strategy, hands-on science communication, and
the communication of the planet definition discussion; 25. Getting a
word in edgeways: the survival of discourse in audiovisual astronomy;
26. Critical evaluation of the new Hall of Astronomy; 27. Revitalizing
astronomy teaching through research on student understanding; Poster
abstracts; Part III. Effective Use of Instruction and Information
Technology: Introduction; 28. ESO's astronomy education program;
29. U.S. student astronomy research and remote observing projects;
30. Global network of autonomous observatories dedicated to student
research; 31. Remote telescopes in education: report of an Australian
study; 32. Visualizing large astronomical data holdings; Poster
abstracts; Part IV. Practical Issues Connected with the Implementation
of the 2003 IAU Resolution: Introduction; 33. Stellar evolution for
students of Moscow University; 34. Astronomy for everybody: An approach
from the CASAO/NAUH view; 35. Toward a new program in astronomy
education in secondary schools in Turkey; 36. Universe awareness
for young children; 37. Education in Egypt and Egyptian responses to
eclipses; 38. Astronomy in the cultural heritage of African societies;
39. Education at the Pierre Auger Observatory: the cinema as a tool in
science education; 40. Freshman seminars: interdisciplinary engagements
in astronomy; 41. Astronomy for teachers; Poster abstracts; Conclusion.
---------------------------------------------------------
Title: Mingantu, 18th-Century Mongol Astronomer and Radioheliograph
Namesake
Authors: Pasachoff, Jay M.
2013AAS...22113003P Altcode:
The 18th-century Mongol astronomer Mingantu (1692-1765) has been
honored with a city named after him and a nearby solar telescope
array. During the IAU/Beijing, my wife and I went to the new
Chinese solar radioheliograph, the Mingantu Observing Station,
in Inner Mongolia, ~400 km northwest of Beijing, a project of the
National Astronomical Observatories, Chinese Academy of Sciences. It
currently contains 40 dishes each 4.5 m across, with a correlator
from Beijing. Within a year, 60 2-m dishes will be added. We passed by
the 12-century ruins of Xanadu (about 20 km north of Zhangbei) about
halfway. The radioheliograph is in a plane about 1 km across, forming
a three-armed spiral for interferometric solar mapping, something
colleagues and I had carried out with the Jansky Very Large Array,
taking advantage of the lunar occultation before annularity at the 20
May 2012 solar eclipse. In the central square of Mingantu city, a statue
~10-m high of the Mongol astronomer Mingantu appears. Its base bears
a plaque ~1-m high of IAU Minor Planet Circular MPC 45750 announcing
the naming in 2002 of asteroid 28242 Mingantu, discovered at a Chinese
observatory in 1999. Mingantu carried out orbital calculations, mapping,
mathematical work on infinite series, and other scientific research. He
is honored by a modern museum behind the statue. The museum's first 40%
describes Mingantu and his work, and is followed by some artifacts
of the region from thousands of years ago. The final, large room
contains a two-meter-square scale model of the radioheliograph,
flat-screen televisions running Solar Dynamics Observatory and other
contemporary visualizations, orreries and other objects, and large
transparencies of NASA and other astronomical imagery. See my post at
http://www.skyandtelescope.com/community/skyblog/newsblog/ specfically
Astro-Sightseeing_in_Inner_Mongolia-167712965.html. We thank Yihua
Yan for arranging the visit and Wang Wei (both NAOC) for accompanying
us. My solar research is supported by grant 1047726 from the Solar
Research Program/Atmospheric and Geospace Sciences Division/NSF. I am
also grateful for a NSF travel grant through AAS.
---------------------------------------------------------
Title: Syzygy x 3
Authors: Pasachoff, Jay M.
2013obha.book....9P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The 2012 Transit of Venus: A Closer Look at the Cytherean
Aureole
Authors: Edelman, Eric; Pasachoff, J. M.; Schneider, G.; Babcock,
B. A.; Lu, M.; Reardon, K.; Widemann, T.; Tanga, P.; Dantowitz, R.
2013AAS...22135304E Altcode:
The 2012 Transit of Venus provided a new opportunity to study the
events that occur during the ingress and egress of transit in greater
detail. The Venus Twilight Experiment is a group that was formed to
analyze the twilight phenomena of Venus through close and careful
observation of planet’s 21st century transits. One particular object
of interest to this group is the Cytherean aureole, or the arc of light
caused by refraction of the Sun’s light through Venus’s upper
atmosphere. A goal associated with the study of this aureole is to
measure how the brightness of the atmosphere changes over time and as
a function of latitude on Venus with the use of the multitude of images
taken of the planet near the beginning and end of the transit. In order
to further along this goal, I was tasked with sorting, processing,
and aligning the images taken by the coronagraph used on the 2012
Williams College Transit of Venus Expedition at Haleakala, Hawaii. Our
observations through a B filter will be compared with observations
through VRI-filter observations from other coronagraphs in the set. This
was research was performed with the support of the Keck Northeast
Astronomy Consortium, sponsored by the NSF and the Keck foundation. The
expedition to Haleakala and Sac Peak was sponsored by the Committee
for Research and Exploration/National Geographic Society. Some funds
for the IBIS carbon-dioxide filter came from NASA/AAS's Small Research
Grant Program. We thank Rob Ratkowski, Stan Truitt, Rob Lucas, Aram
Friedman, and Eric Pilger '82 for assistance with Haleakala observing.
---------------------------------------------------------
Title: Solar Eclipses Observed from Antarctica
Authors: Pasachoff, Jay M.
2013IAUS..288..313P Altcode:
Aspects of the solar corona are still best observed during totality of
solar eclipses, and other high-resolution observations of coronal active
regions can be observed with radio telescopes by differentiation of
occultation observations, as we did with the Jansky Very Large Array
for the annular solar eclipse of 2012 May 20 in the US. Totality
crossing Antarctica included the eclipse of 2003 November 23, and
will next occur on 2021 December 4; annularity crossing Antarctica
included the eclipse of 2008 February 7, and will next occur on 2014
April 29. Partial phases as high as 87% coverage were visible and
were imaged in Antarctica on 2011 November 25, and in addition to
partial phases of the total and annular eclipses listed above, partial
phases were visible in Antarctica on 2001 July 2011, 2002 December 4,
2004 April 19, 2006 September 22, 2007 September 11, and 2009 January
26, and will be visible on 2015 September 13, 2016 September 1, 2017
February 26, 2018 February 15, and 2020 December 14. On behalf of the
Working Group on Solar Eclipses of the IAU, the poster showed the solar
eclipses visible from Antarctica and this article shows a subset (see
www.eclipses.info for the full set). A variety of investigations of the
Sun and of the response of the terrestrial atmosphere and ionosphere
to the abrupt solar cutoff can be carried out at the future eclipses,
making the Antarctic observations scientifically useful.
---------------------------------------------------------
Title: The Comets of Caroline Herschel (1750-1848), Sleuth of the
Skies at Slough
Authors: Olson, Roberta J. M.; Pasachoff, Jay M.
2012arXiv1212.0809O Altcode:
In this paper, we discuss the work on comets of Caroline Herschel,
the first female comet-hunter. After leaving Bath for the environs
of Windsor Castle and eventually Slough, she discovered at least
eight comets, five of which were reported in the Philosophical
Transactions of the Royal Society. We consider her public image,
astronomers' perceptions of her contributions, and the style of her
astronomical drawings that changed with the technological developments
in astronomical illustration.
---------------------------------------------------------
Title: A Coral Sea Rehearsal for the Eclipse Megamovie
Authors: Hudson, H. S.; Davey, A. R.; Ireland, J.; Jones, L.; Mcintosh,
S. W.; Paglierani, R.; Pasachoff, J. M.; Peticolas, L. M.; Russell,
R. M.; Suarez Sola, F. I.; Sutherland, L.; Thompson, M. J.
2012AGUFMSH11C..06H Altcode:
The "Eclipse on the Coral Sea" - 13/14 November 2012 (GMT/Australia)
- will have happened already. Our intention is to have used this
opportunity as a trial run for the eclipse in 2017, which features
1.5 hours of totality across the whole width of the continental
US. Conceived first and foremost as an education and public outreach
activity, the plan is to engage the public in solar science and
technology by providing a way for them to include images they have taken
of the solar eclipse, into a movie representation of coronal evolution
in time. This project will assimilate as much eclipse photography as
possible from the public. The resulting movie(s) will cover all ranges
of expertise, and at the basic smartphone or hand-held digital camera
level, we expect to have obtained a huge number of images in the case
of good weather conditions. The capability of modern digital technology
to handle such a data flow is new. The basic purpose of this and the
2017 Megamovie observations is to explore this capability and its
ability to engage people from many different communities in the solar
science, astronomy, mathematics, and technology. The movie in 2017,
especially, may also have important science impact because of the
uniqueness of the corona as seen under eclipse conditions. In this
presentation we will describe our smartphone application development
(see the "Transit of Venus" app for a role model here). We will also
summarize data acquisition via both the app and more traditional web
interfaces. Although for the Coral Sea eclipse event we don't expect to
have a movie product by the time of the AGU, for the 2017 event we do
intend to assemble the heterogenous data into beautiful movies within a
short space of time after the eclipse. These movies may have relatively
low resolution but would extend to the base of the corona. We encourage
participation in the 2012 observations, noting that no total eclipse,
prior to 2017, will occur in a region with good infrastructure for
extended observations. The National Center for Atmospheric Research is
sponsored by the National Science Foundation. The Megamovie project
is supported by NSF grant AGS-1247226, and JMP's eclipse work about
the eclipses of 2012 is supported by NSF grant AGS-1047726.
---------------------------------------------------------
Title: Venus's Atmosphere: Discoverer Debatable I
Authors: Pasachoff, Jay M.; Sheehan, William
2012S&T...124d...8P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: A Glorious Transit of Venus
Authors: Pasachoff, Jay M.
2012S&T...124d..20P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The Venus Twilight Experiment: Probing The Mesosphere In 2004
And 2012
Authors: Tanga, Paolo; Widemann, T.; Ambastha, A.; Babcock, B. A.;
Berthier, J.; Bouley, S.; Braga-Ribas, F.; Brasch, K.; Burke, W.;
Colas, F.; Fukuhara, T.; Fulham, L.; Imai, M.; Lu, M.; Machado, P.;
Maquet, L.; Pasachoff, J. M.; Roberts, J.; Schneider, G.; Sheehan,
W.; Sigismondi, C.; Thouvenin, N.; Vachier, F.; Veillet, C.; Wang, X.
2012DPS....4450807T Altcode:
During the Venus transit in 2004 several observers collected data
useful to the characterization of the mesosphere of the planet, by
observing the solar light refracted at the corresponding altitude
range. The "aureole" thus formed, is observable during the ingress
and egress phases of the transit, when Venus is crossing the solar
limb. For the 2012 opportunity we prepared a set of coronagraphs
to obtain multi-wavelength, space- and time-resolved photometry of
the aureole, in collaboration with other space- and ground-based
campaigns. The coronagraphs were distributed in the visibility area
around the Pacific, over eight sites where local logistic support and
scientific expertise were present. Several sites obtained useful data
at frame rates of several images/sec. We will give an account of the
campaign presenting first results obtained at 450, 535, 607 and 760 nm
(FWHM 10 nm). A comparison with data collected at the 2004 transit shows
that variations in the aspects of the aureole are present. These can
be linked to variations in the vertical distribution of the absorbers
(aerosols and cloud-top level). A common feature in both the recent
transits is the presence of a brightness peak at high latitude, which
was imaged several minutes before and after first and last contact,
respectively. The historical record of the aureole contains hints of
varying features and a constant polar-spot presence, which can now be
interpreted in the light of the measurements obtained in 2004 and 2012.
---------------------------------------------------------
Title: Pluto’s Atmosphere from the 23 June 2011 Stellar Occultation:
Airborne and Ground Observations
Authors: Person, Michael J.; Bosh, A. S.; Levine, S. E.; Gulbis,
A. A. S.; Zangari, A. M.; Zuluaga, C. A.; Dunham, E. W.; Pasachoff,
J. M.; Babcock, B. A.; Pandey, S.; Armhein, D.; Sallum, S.; Tholen,
D. J.; Collins, P.; Bida, T.; Taylor, B.; Wolf, J.; Meyer, A.;
Pfueller, E.; Wiedermann, M.; Roesser, H.; Lucas, R.; Kakkala, M.;
Ciotti, J.; Plunkett, S.; Hiraoka, N.; Best, W.; Pilger, E. L.;
Miceli, M.; Springmann, A.; Hicks, M.; Thackeray, B.; Emery, J.;
Rapoport, S.; Ritchie, I.
2012DPS....4430402P Altcode:
The double stellar occultation by Pluto and Charon of 2011 June 23 was
observed from numerous ground stations as well as the Stratospheric
Observatory for Infrared Astronomy (SOFIA). This first airborne
occultation observation since 1995 resulted in the best occultation
chords recorded for the event, in three optical wavelength bands. The
data obtained from SOFIA were combined with chords obtained from
the ground at the IRTF (including a full spectral light curve),
the USNO--Flagstaff Station, and Leeward Community College to give a
detailed profile of Pluto’s atmosphere. The data show a return to
the distinct upper and lower atmospheric regions with a knee, or kink
in the light curves separating them as was observed in 1988 (Millis et
al. 1993), rather than the smoothly transitioning bowl-shaped light
curves of recent years (Elliot et al. 2007). We analyze the upper
atmosphere by fitting a model to all of the light curves obtained,
resulting in a half-light radius of 1288 ± 1 km. We analyze the
lower atmosphere with two different methods to provide results under
the separate assumptions of particulate haze and a strong thermal
gradient. Results indicate that the lower atmosphere evolves on short
seasonal timescales, changing between 1988 and 2006, and then returning
to approximately the 1988 state in 2011, though at significantly higher
pressures. Throughout these changes, the upper atmosphere remains
remarkably stable in structure, again excepting the overall pressure
changes. No evidence of the onset of atmospheric collapse predicted by
frost migration models is yet seen, and the atmosphere appears to be
remaining at a stable pressure level. This work was supported in part by
NASA Planetary Astronomy grants to MIT (NNX10AB27G) and Williams College
(NNX08AO50G, NNH11ZDA001N), as well as grants from USRA (#8500-98-003)
and Ames Research (#NAS2-97-01) to Lowell Observatory.
---------------------------------------------------------
Title: The 2012 Transit of Venus for Cytherean Atmospheric Studies
and as an Exoplanet Analog
Authors: Pasachoff, Jay M.; Schneider, G.; Babcock, B. A.; Lu, M.;
Reardon, K. P.; Widemann, T.; Tanga, P.; Dantowitz, R.; Willson,
R.; Kopp, G.; Yurchyshyn, V.; Sterling, A.; Scherrer, P.; Schou, J.;
Golub, L.; Reeves, K.
2012DPS....4450806P Altcode:
We worked to assemble as complete a dataset as possible for the
Cytherean atmosphere in collaboration with Venus Express in situ
and to provide an analog of spectral and total irradiance exoplanet
measurements. From Haleakala, the whole transit was visible in
coronal skies; our B images showed the evolution of the visibility
of Venus's atmosphere and of the black-drop effect, as part of the
Venus Twilight Experiment's 9 coronagraphs distributed worldwide
with BVRI. We imaged the Cytherean atmosphere over two minutes before
first contact, with subarcsecond resolution, with the coronagraph and
a separate refractor. The IBIS imaging spectrometer at Sacramento
Peak Observatory at H-alpha and carbon-dioxide also provided us
high-resolution imaging. The NST of Big Bear Solar Observatory
also provided high-resolution vacuum observations of the Cytherean
atmosphere and black drop evolution. Our liaison with UH's Mees Solar
Observatory scientists provided magneto-optical imaging at calcium
and potassium. Spaceborne observations included the Solar Dynamics
Observatory's AIA and HMI, and the Solar Optical Telescope (SOT)
and X-ray Telescope (XRT) on Hinode, and total-solar-irradiance
measurements with ACRIMSAT and SORCE/TIM, to characterize the
event as an exoplanet-transit analog. Our expedition was sponsored
by the Committee for Research and Exploration/National Geographic
Society. Some of the funds for the carbon-dioxide filter for IBIS were
provided by NASA through AAS's Small Research Grant Program. We thank
Rob Lucas, Aram Friedman, and Eric Pilger '82 for assistance with
Haleakala observing, Rob Ratkowski of Haleakala Amateur Astronomers
for assistance with equipment and with the site, Stan Truitt for the
loan of his Paramount ME, and Steve Bisque/Software Bisque for TheSky
X controller. We thank Joseph Gangestad '06 of Aerospace Corp., a
veteran of our 2004 expedition, for assistance at Big Bear. We thank
the Lockheed Martin Solar and Astrophysics Laboratory and Hinode
science and operations teams for planning and support.
---------------------------------------------------------
Title: Assymetry in the Polar Mesosphere Revealed by the 2012 Venus
Transit Aureole
Authors: Widemann, Thomas; Tanga, P.; Reardon, K. P.; Limaye, S.;
Wilson, C.; Vandaele, A.; Wilquet, V.; Mahieux, A.; Robert, S.;
Pasachoff, J. M.; Schneider, G.
2012DPS....4450808W Altcode:
Close to ingress and egress phases, the fraction of Venus disk projected
outside the solar photosphere appears outlined by an irregular thin
arc of light called the "aureole." We have shown that the deviation
due to refraction and the aureole intensity are related to the local
density scale height and the altitude of the refraction layer (Tanga
et al. 2012). Since the aureole brightness is the quantity that can be
measured during the transit, an appropriate model allows us to determine
both parameters. We now compare this model developed for the 2004
data to the first results of 2012 campaign. Ingress pictures of NASA's
SDO/HMI observations, OP-OCA/VTE coronagraph observations at Haleakala
and Lowell stations, and Dunn/IBIS observations at Sacramento Peak, NM,
show latitudinal structure of the aureole during the ingress phase of
the Venus transit. For the HMI data, the temporal cadence is 3.75 sec
and the pixel scale is 0.5 arcsec/pixel. The polar region, significantly
brighter in initial phases due to the larger scale height of the polar
mesosphere, appears consistently offset toward morning terminator by
about 15 deg. latitude, peaking at 75N at 6:00 local time. This result
reflects local latitudinal structure in the polar mesosphere, either in
temperature or aerosol altitude distribution. Relation with ESA / Venus
Express / SOIR simultaneous measurements and dynamical interpretation
will be discussed at the meeting. Tanga et al. 2012, Icarus 218, 207-219
---------------------------------------------------------
Title: Print, Web, And Podcast Tov Public Outreach
Authors: Pasachoff, Jay M.
2012DPS....4441110P Altcode:
As part of alerting the general public to the subtly spectacular
transit of Venus as an intellectual marvel not available to us
from Earth until AD 2117/2125, in addition to our scientific plans
(Pasachoff et al., this meeting), I provided: (1) an article in
the children's magazine Odyssey (May/June 2011); (2) a discussion
in National Geographic Society's BreakingOrbit blog (March 1,
2011); (3) and a year's advance notice as "June 5: Transit of
Venus," 365daysofastronomy.org. (4) Nantes DPS: I participated in
"Transits of Venus in Public Education and Contemporary Research"
(http://transitofvenus.nl/wp/2011/10/16/four-giants-talk-about-transits).
(5) 22-minute lecture on the Phi Beta Kappa website:
http://www.pbk.org/home/playpodcast.aspx?id=772. (6) E/PO summary
at Historical Astronomy Division News, #79, October. Closer
to the event, I had a (7) Comment in Nature ("Transit of
Venus: Last Chance to See," Nature 485, 303-304) and (8, 9)
articles in Physics World, 25, 36-41; and Scientific American,
http://www.scientificamerican.com/article.cfm?id=transit-venus-june-5).
The day before the transit, (10) I had a radio/podcast Academic Minute
(http://www.wamc.org/post/dr-jay-pasachoff-williams-college). (11)
On transit day, I had an Op-Ed piece in The
New York Times ("Learning from Celestial Beauty,"
http://www.nytimes.com/2012/06/05/opinion/learning-from-celestial-beauty.html)
that was seen by largely a non-scientific audience. Subsequently,
(12) I gave a Keck-Observatory-sponsored Waimea general-public lecture
(http://keckobservatory.org/news/video_venus_transits_past_present_future),
and (13) an invited public lecture at the AAS meeting in Anchorage
(http://aas.org/meetings/aas220/video_session_127). I had a podcast on
(14) 365daysofastronomy.org (June 29). (15) My article for Sky &
Telescope appeared in its October issue. (16) My editorial "Syzygy
x 3" will be in RASC Observer's Handbook 2013. (16) These efforts
as well as links to history and science of transits of Mercury and
Venus are at http://sites.williams.edu/transitofvenus2012/links/ as
part of my website http://www.transitofvenus.info. Acknowledgments:
My expeditions to the 2004 and 2012 transits of were supported by
grants from the Committee for Research and Exploration of the National
Geographic Society.
---------------------------------------------------------
Title: Probing Pluto’s Upper Atmosphere: a 2011 Occultation Graze
in Visible Images and Infrared Spectra
Authors: Gulbis, Amanda A. S.; Emery, J. P.; Person, M. J.; Bosh,
A. S.; Zuluaga, C. A.; Pasachoff, J. M.; Babcock, B. A.
2012DPS....4430403G Altcode:
On 2011 June 23, a 14.43 UCAC2 magnitude star was occulted by Pluto
as observed from multiple sites. Observations made at NASA’s 3-m
Infrared Telescope Facility (IRTF) on Mauna Kea, Hawaii, detected a
full occultation of the star by Charon followed by an atmospheric graze
by Pluto. Data were taken simultaneously with MORIS (the MIT Optical
Rapid Imaging System; Gulbis et al. 2011, PASP, 123, 461) and SpeX
(Rayner et al. 2003, PASP, 115, 362). MORIS recorded visible images
of a 1 arcmin by 1 arcmin field of view, with an effective central
wavelength of 0.74 microns, at a cadence of 0.3 seconds and negligible
deadtime. Low-resolution spectral IR data of the occultation star and
a comparison were taken with SpeX, using the 1.6 arcsec slit, over
the range of 0.9-2.5 microns, at a cadence of 1.5 seconds including
approximately 0.75 seconds deadtime. Pluto’s lower atmosphere has been
evolving since the first definitive detection in 1988 (e.g., Elliot et
al. 2007, AJ, 134,1; Young et al. 2008, AJ, 136, 1757). Possibilities
for explaining the lower atmospheric structure include a steep thermal
gradient and/or extinction, the latter of which can be characterized as
a dependence between occultation flux and wavelength. This graze reached
a minimum normalized flux level of roughly 0.35, serving primarily as
a probe of Pluto’s upper atmosphere. However, there appears to be
a slight dependence of flux with wavelength in the minimum portion
of the graze. We will present the IRTF lightcurves and an analysis
of the wavelength-resolved data. Funding for this work was provided
in part by the South African National Research Foundation and NASA
grants NNX08AO50G & NNH11ZDA001N (Williams), NNX10AB27G (MIT),
and NNX10AB23G (UT).
---------------------------------------------------------
Title: Venus Twilight Experiment : Observation and analysis of the
aureole during the 2012 transit
Authors: Widemann, T.; Tanga, P.; Sicardy, B.; Machado, P.;
Braga-Ribas, F.; Veillet, C.; Pasachoff, J.; Colas, F.; Vachier, F.;
Bouley, S.; Maquet, L.; Berthier, J.; Fukuhara, T.; Luz, D.
2012epsc.conf..412W Altcode: 2012espc.conf..412W
On 5-6 June 2012, Venus will be transiting the Sun for the last
time in this century. This unique opportunity, besides offering
the opportunity of investigating the mesosphere of the planet, also
provides a significant nearby analog of exoplanet transits. Several
studies using the transmission spectroscopy technique have provided
significant insights into the atmospheric composition, structure,
and dynamics of hot giant exoplanets. In this context, Venus is our
closest model for a telluric exoplanet.
---------------------------------------------------------
Title: Expeditions to Death and Disaster: Chappe d'Auteroche and
Charles Green at the 1769 Transit of Venus
Authors: Pasachoff, Jay M.
2012icha.book...24P Altcode:
Scientific expeditions usually bring back information or specimens
that forward human knowledge. We also prefer them to bring back the
humans in good shape, but that does not always occur. I discuss the
expeditions to Siberia in 1761 and to Baja California in 1769 by the
French abbé Jean Chappe d'Auteroche and to Tahiti in 1769 by the
English astronomer Charles Green, accompanying Captain James Cook,
to observe the transits of Venus. Neither Chappe d'Auteroche nor
Green survived their expeditions. Chappe managed to hang on after
the transit to see an eclipse of the Moon about two weeks later, and
it is said that since “the intent of his voyage was fulfilled, and
the fruit of his observations secured,” he “died content,” since
“he saw nothing more to wish for.” Green died of dysentery caught
in Batavia (now in Indonesia) on the continuation of his expedition
with Capt. Cook on the ship Endeavour after the transit.
---------------------------------------------------------
Title: New Obituary Policy for the American Astronomical Society
Authors: Pasachoff, Jay M.
2012opsa.book..319P Altcode:
The American Astronomical Society has a permanent website with
obituaries of nearly all its members who have died since 1990.The
Vice Chair of the Historical Astronomy Division (HAD) is tasked with
selecting authors and editing the obituaries, which are posted by the
AAS headquarters staff on a site; an alphabetical index appears at
the Historical Astronomy Division's site, which is linked from their
top-level page. The HAD was asked to be in charge of obituaries by the
AAS Council in 1990.Most obituaries are in the vicinity of 800 words,
but longer essays are allowable for selected individuals.
---------------------------------------------------------
Title: Transit of Venus: Last chance to see
Authors: Pasachoff, Jay M.
2012Natur.485..303P Altcode:
The June 2012 transit of Venus across the Sun offers an opportunity to
check our methods for spotting distant planets crossing far-away stars,
says Jay M. Pasachoff.
---------------------------------------------------------
Title: The Black Drop Effect
Authors: Pasachoff, Jay M.
2012S&T...123R...8P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Spectroscopic Coronal Observations During the Total Solar
Eclipse of 11 July 2010
Authors: Voulgaris, A. G.; Gaintatzis, P. S.; Seiradakis, J. H.;
Pasachoff, J. M.; Economou, T. E.
2012SoPh..278..187V Altcode: 2012arXiv1202.1535V
The flash spectra of the solar chromosphere and corona were measured
with a slitless spectrograph before, after, and during the totality
of the solar eclipse of 11 July 2010, at Easter Island, Chile. This
eclipse took place at the beginning of Solar Cycle 24, after an extended
minimum of solar activity. The spectra taken during the eclipse show a
different intensity ratio of the red and green coronal lines compared
with those taken during the total solar eclipse of 1 August 2008,
which took place toward the end of Solar Cycle 23. The characteristic
coronal emission line of forbidden Fe XIV (5303 Å) was observed on
the east and west solar limbs in four areas relatively symmetrically
located with respect to the solar rotation axis. Subtraction of
the continuum flash-spectrum background led to the identification
of several extremely weak emission lines, including forbidden Ca XV
(5694 Å), which is normally detected only in regions of very high
excitation, e.g., during flares or above large sunspots. The height of
the chromosphere was measured spectrophotometrically, using spectral
lines from light elements and compared with the equivalent height of the
lower chromosphere measured using spectral lines from heavy elements.
---------------------------------------------------------
Title: Transits of Venus and Mercury: Exoplanet Analogs in Our
Solar System
Authors: Pasachoff, Jay M.
2012AAS...22012701P Altcode:
Since Johannes Kepler's predictions of transits of Mercury and Venus
in 1631, and observations by Jeremiah Horrocks and William Crabtree
of the 1639 transit of Venus, only 5 other transits of Venus have
been observed: in 1761 and 1769, 1874 and 1882, and 2004. Expeditions
were sent all over the world for the 18th and 19th century transits to
follow the methods of Halley and others to determine the Astronomical
Unit, giving the size and scale of the solar system, arguably the most
important problem in astronomy for centuries. I will discuss how the
infamous black-drop effect bedeviled astronomers in that quest for
an accurate A.U., and how Glenn Schneider and I explained the effect
through satellite observations of transits of Mercury, showing that
it was not simply caused by the Cytherean atmosphere. During the 2004
transit, we worked with Richard Willson of ACRIMsat to detect the 0.1%
drop in the Total Solar Irradiance, showing the effect of solar limb
darkening, positioning such observations of transits of Venus and
of Mercury as analogs to exoplanet transits. Our observations of the
atmosphere of Venus with NASA's Transition Region and Coronal Explorer
in 2004 led us to plan extensive observations of Venus's atmosphere
and other phenomena during the June 5, 2012, transit of Venus, the
last to be visible from Earth until 2117. We will have used NASA's
Solar Dynamics Observatory, Hinode, ACRIMsat, and other spacecraft,
and ground-based solar telescopes at Sacramento Peak, Kitt Peak, Big
Bear, and Haleakala to observe the transit; I hope to give preliminary
reports on these observations during this talk. Further, I will discuss
the plans of Ehrenreich and colleagues for Hubble observations of this
transit and our hopes of detecting transits of Venus and Earth as seen
from Jupiter and Saturn over the next few years.
---------------------------------------------------------
Title: Lomonosov, the discovery of Venus's atmosphere, and the
eighteenth-century transits of Venus
Authors: Pasachoff, Jay M.; Sheehan, William
2012JAHH...15....3P Altcode:
The discovery of Venus's atmosphere has been widely attributed to
the Russian academician M.V. Lomonosov from his observations of the
1761 transit of Venus from St. Petersburg. Other observers at the
time also made observations that have been ascribed to the effects
of the atmosphere of Venus. Though Venus does have an atmosphere one
hundred times denser than the Earth's and refracts sunlight so as to
produce an 'aureole' around the planet's disk when it is ingressing
and egressing the solar limb, many eighteenth century observers also
upheld the doctrine of cosmic pluralism: believing that the planets
were inhabited, they had a preconceived bias for believing that
the other planets must have atmospheres. A careful re-examination of
several of the most important accounts of eighteenth century observers
and comparisons with the observations of the nineteenth century and
2004 transits shows that Lomonosov inferred the existence of Venus's
atmosphere from observations related to the 'black drop', which has
nothing to do with the atmosphere of Venus. Several observers of the
eighteenth-century transits, includ-ing Chappe d'Auteroche, Bergman,
and Wargentin in 1761 and Wales, Dymond, and Rittenhouse in 1769,
may have made bona fide observations of the aureole produced by the
atmosphere of Venus. Therefore, it appears that several observers-but
not Lomonosov-should receive credit for first detecting the aureole
due to refraction of sunlight by the atmosphere of Venus during
a transit. This crucial observation occurred almost three decades
before Johann Schroeter independently demonstrated the existence of the
atmosphere of Venus from his analysis of extensions of the semicircle
of light of the planet near inferior conjunction, which are produced
by back-scattering of light by aerosol-sized particles.
---------------------------------------------------------
Title: Sunlight refraction in the mesosphere of Venus during the
transit on June 8th, 2004
Authors: Tanga, P.; Widemann, T.; Sicardy, B.; Pasachoff, J. M.;
Arnaud, J.; Comolli, L.; Rondi, A.; Rondi, S.; Sütterlin, P.
2012Icar..218..207T Altcode: 2011arXiv1112.3136T
Many observers in the past gave detailed descriptions of the telescopic
aspect of Venus during its extremely rare transits across the Solar
disk. In particular, at the ingress and egress, the portion of the
planet’s disk outside the Solar photosphere has been repeatedly
perceived as outlined by a thin, bright arc (“aureole”). Those
historical visual observations allowed inferring the existence of
Venus’ atmosphere, the bright arc being correctly ascribed to the
refraction of light by the outer layers of a dense atmosphere. On June
8th, 2004, fast photometry based on electronic imaging devices allowed
the first quantitative analysis of the phenomenon. Several observers
used a variety of acquisition systems to image the event - ranging from
amateur-sized to professional telescopes and cameras - thus collecting
for the first time a large amount of quantitative information on this
atmospheric phenomenon. In this paper, after reviewing some elements
brought by the historical records, we give a detailed report of the
ground based observations of the 2004 transit. Besides confirming the
historical descriptions, we perform the first photometric analysis of
the aureole using various acquisition systems. The spatially resolved
data provide measurements of the aureole flux as a function of the
planetocentric latitude along the limb. A new differential refraction
model of solar disk through the upper atmosphere allows us to relate
the variable photometry to the latitudinal dependency of scale-height
with temperature in the South polar region, as well as the latitudinal
variation of the cloud-top layer altitude. We compare our measurements
to recent analysis of the Venus Express VIRTIS-M, VMC and SPICAV/SOIR
thermal field and aerosol distribution. Our results can be used a
starting point for new, more optimized experiments during the 2012
transit event.
---------------------------------------------------------
Title: Transits Of Venus: 1639, 1761, 1769, 1874, 1882, 2004, And 2012
Authors: Pasachoff, Jay M.
2012AAS...219.9001P Altcode:
Transits of Venus are exceedingly rare predictable astronomical events,
with only six having been observed since Jeremiah Horrox corrected
Johannes Kepler's Rudolphine Tables and observed the transit of
1639. Edmond Halley's 1716 method of finding the size and scale of the
Solar System and thus of the Universe led to hundreds of 18th-century
and 19th-century transit-of-Venus expeditions for each event. I
discuss the history and importance of the transit observations,
and how spacecraft observations of the 1999 transit of Mercury,
repeated at the 2003 and 2006 transits, led to the solution of the
black-drop effect problem that had prevented Halley's method from
reaching its desired accuracy and thus solution of the noble problem
of astronomy to find the size and scale of the solar system. Other
spacecraft observations of the 2004 transit of Venus have led to
an analysis of how Venus's atmosphere becomes visible for about 25
minutes before second contact and after third contact, and links with
prior historical claims, mostly invalid, to have discovered Venus's
atmosphere at transits. Total-solar-irradiance spacecraft observations
at the 2004 Venus transit link to exoplanet discoveries with NASA's
aptly named Kepler Mission and ESA's CoRoT. I further link previous
transit observations to planned observations for the June 5/6, 2012,
Venus transit and the May 9, 2016, Mercury transit, together providing
a historical basis for 22nd-century astronomers preparing to observe
the December 10, 2117, Venus transit. <P />My observations at the
2004 and 2012 transits of Venus were and will be supported in large
part by grants from the Committee for Research and Exploration of the
National Geographic Society. My solar observations were supported in
part by NASA grant NNG04GK44G for work with the TRACE spacecraft and
NASA Marshall grant NNX10AK47A and planetary work supported in part
by NNX08AO50G from NASA Planetary Astronomy.
---------------------------------------------------------
Title: Ten years of the high-resolution imaging process of the
eclipse white-light corona
Authors: Rusin, V.; Saniga, M.; Pasachoff, J.; Druckmuller, M.;
Belik, M.
2011AGUFMSH33A2031R Altcode:
The corona is the uppermost part of the Sun's atmosphere and, up to
now, total solar eclipses provide the best conditions for observing it
from Earth's surface. The white-light corona (WLC) is the scattered
light of the photosphere off free electrons and it dominates in the
regions up to 2-3 solar radii. As the motion of electrons is governed
by magnetic fields of the corona, and these fields are sensitive to the
phase of the solar cycle, the WLC exhibits many faces and a variety of
fine structures throughout a cycle. When observing the WLC, one faces
problems due to a steep gradient of its brightness and difficulties in
discerning individual structures. Our contribution presents a set of
unique eclipse pictures of the WLC that were processed by Druckmüller's
method; they cover the period from 2001 to 2010 and thus give a fairly
good idea about the changes in both the shape and the fine structure
of the WLC over a whole solar cycle.
---------------------------------------------------------
Title: Structure and Dynamics of the 2009 July 22 Eclipse White-light
Corona
Authors: Pasachoff, J. M.; Rušin, V.; Saniga, M.; Druckmüllerová,
H.; Babcock, B. A.
2011ApJ...742...29P Altcode:
The white-light corona (WLC) during the total solar eclipse of 2009
July 22 was observed by several teams in the Moon's shadow stretching
from India and China across the Pacific Ocean with its many isolated
islands. We present a comparison of the WLC as observed by eclipse
teams located in China (Shanghai region) and on the Enewetak Atoll
in the Marshall Islands, with observations taken 112 minutes apart,
combined with near-simultaneous space observations. The eclipse was
observed at the beginning of solar cycle 24, during a deep solar minimum
(officially estimated as 2008 December according to the smoothed sunspot
number, but very extended). The solar corona shows several different
types of features (coronal holes, polar rays, helmet streamers, faint
loops, voids, etc.), though it was extremely sparse in streamers as
shown from Large-Angle Spectroscopic Coronagraph data. No large-scale
dynamical phenomena were seen when comparing the observations from
the two sites, confirming that the corona was quiescent. We measure
a Ludendorff flattening coefficient of 0.238, typical of solar minimum.
---------------------------------------------------------
Title: Transits of Venus in Public Education and Contemporary Research
Authors: Pasachoff, J. M.
2011epsc.conf.1773P Altcode: 2011DPS....43.1773P
Transits of Venus are among the rarest predictable astronomical event
that humans can enjoy, and the 2012 transit will be visible by almost
all the people on Earth. It is our job as educators to bring out the
thrill of being able to see the tiny dot of Venus silhouetted against
the solar disk even with just a simple eye-protection filter. My Website
at http://www.transitofvenus.info brings together not only historical
information about the five previous transits of Venus that were observed
through the 20th century--1639, 1761, 1769, 1874, and 1882--but also
the scientific work carried out at the 2004 transit and at recent
transits of Mercury. Based on space observations of the 1999 transit
of Mercury with NASA's Transition Region and Coronal Explorer (TRACE),
Glenn Schneider and I provided proof of the contemporary explanation of
the black-drop effect as an amalgam of instrumental point-spread and
solar limb-darkening [1]. Based on observations of the changes in the
total solar irradiance during the transit, we provided an analysis of
this solar-system analogue to exoplanet transits [2]. High-resolution
(0.5 arcsec pixels) observations of ingress and egress with TRACE
during the 2004 transit provided information about the visibility of
Venus's atmosphere through its refraction of sunlight, interpreted
with Venus Express observations [3]. We anticipate observing the 2012
transit with groundbased facilities of the University of Hawaii at
Haleakala, and of the National Solar Observatory at Sacramento Peak,
and Kitt Peak, as well as with NASA and JAXA spacecraft, including Solar
Dynamics Observatory, ACRIMsat, and Hinode. The Program Group on Public
Education on the Occasions of Eclipses and Transits of Commission 46
on Education and Development of the International Astronomical Union,
which I chair, looks forward to participating in Education and Public
Outreach efforts related to the 2012 transit.
---------------------------------------------------------
Title: The Double-Double Pluto-Charon and Pluto-Hydra Predicted
Stellar Occultations of June 2011
Authors: Pasachoff, J. M.; Babcock, B. A.; Pandey, S.; Amrhein, D.;
Person, M. J.; Gulbis, A. A. S.; Bosh, A. S.; Zuluaga, C. A.; Sallum,
S.; Tholen, D. J.; Lucas, R.; Kakkala, M.; Ciotti, J.; Plunkett, S.;
Hiraoka, N.; Best, W.; Pilger, E. J.; Miceli, M.; Levine, S.
2011epsc.conf.1821P Altcode: 2011DPS....43.1821P
MIT astrometry predicted an occultation of Pluto and Charon within
11 minutes of each other on 23 June 2011 and an occultation of Pluto
on 27 June 2011 with an occultation of Hydra following in a narrow
shadow-path 33 minutes later. Our Williams-MIT team organized a
network of telescopes around the Pacific-Asia region, including use
of two telescopes in Hawaii, on which we report here. On 23 June,
we successfully observed a 49 s occultation of Charon at 2 Hz with
our Portable Occultation, Eclipse, and Transit System, POETS, from
Leeward Community College's 0.5-m telescope in Pearl City. Our site at
Windward Community College in Kaneohe with its 0.4-m telescope and a
POETS was cloudy for both events, as was the Leeward Community College
site for the second event with a 0.3-m telescope, used because the event
was only 16° above the horizon, too low for their larger telescope,
and a POETS. We place our successful Charon occultation in the context
of observations by others, including our collaborators on SOFIA and
observing with IRTF, and we discuss the predictions, observations, and
prospective scientific value of the predicted double events with Pluto
(radius 1400 km) and Charon (radius 605 km) prospectively occulting
the same star on 23 June 23 UT and Pluto and Hydra (possibly only 50
km in radius) prospectively occulting a different star on 27 June UT.
---------------------------------------------------------
Title: Measured Pluto-Charon Offset from the Stellar Occultations
of 23 June 2011
Authors: Zuluaga, C. A.; Person, M. J.; Bosh, A. S.; Levine, S. E.;
Gulbis, A. A. S.; Zangari, A. M.; Pasachoff, J. M.; Babcock, B. A.;
Pandey, S.; Amrhein, D.; Sallum, S.; Dunham, E. W.; Tholen, D. J.;
Collins, P.; Bida, T.; Taylor, B.; Lucas, R.; Kakkala, M.; Ciotti,
J.; Plunkett, S.; Hiraoka, N.; Best, W.; Pilger, E. J.; Miceli, M.;
Springmann, A.; Hicks, M.; Thackeray, B.; Emery, J.; Rapoport, S.;
Ritchie, I.; Pearson, M.; Mattingly, A.; Brimacombe, J.; Gault, D.;
Jones, R.; Nolthenius, R.; Broughton, J.; Barry, T.
2011epsc.conf.1866Z Altcode: 2011DPS....43.1866Z
We report on our Charon results from the double occultation observed
on 23 June 2011 [1,2,3]. Our group successfully observed the
occultation of the same star, 2UCAC 24677089, by Pluto and Charon
shown in Figure 1. Charon occulted the star first, and its shadow
was offset from that of Pluto by about 1200 km to the north. Thus,
observers on the big island of Hawaii and along most of Baja were
in the double-occultation zone, where occultations by both Pluto
and Charon could be observed. Observers were located around the
globe for this event. In Table 1 we list the sites and instruments
used. Using GPStriggered instrument MORIS [4] at the NASA Infrared
Telescope Facility (IRTF), we were able to record both occultations
within approximately 11 minutes of each other. We obtained Charon-only
light curves at an additional three sites. Observations at Leeward
Community College on Oahu were made using a GPS-triggered Portable
Occultation, Eclipse, and Transit System (POETS [5]). Observers
at Table Mountain Observatory (CA) used a GPS-triggered Portable
Instrument for Capturing Occultations (PICO [6]). Data were acquired
at the U. S. Naval Observatory - Flagstaff Station (AZ) with the USNO
Array Camera, an array of six 2k by 4k chips by e2v. We will analyze
these data to solve for the shape and size of Charon as well as to
how its position relative to Pluto compares to the JPL PLU017 ephemeris.
---------------------------------------------------------
Title: The 22 May 2011 Pluto occultation - observed
Authors: Pasachoff, J. M.; Souza, S. P.; Babcock, B. A.; Pandey, S.;
Hosek, M. W.; Person, M. J.; Gulbis, A. A. S.; Bosh, A. S.; Zuluaga,
C. A.; Ryan, E. V.; Ryan, W. H.; Briggs, J. W.; Winkler, P. F.;
Hoette, V.; Haislip, J.
2011epsc.conf.1784P Altcode: 2011DPS....43.1784P
Based on a prediction from MIT with astrometric observations from the
USNO and Lowell Observatory, we observed the 22 May 2011 UT 06:22
occultation of a star by Pluto (www.stellaroccultations.info and
occult.mit.edu), predicted time. The star occulted was UCAC2 magnitude
15.3, and the event's geocentric velocity was 18.2 km s-1. We used
the 0.6-m telescope of Williams College's Hopkins Observatory in
Williamstown, MA, and one of our Portable Occultation, Eclipse, and
Transit System (POETS) CCD/GPS. The centerline of the predicted path
was just above the north pole, with the southern limit passing through
the U.S. mid-Atlantic, so telescopes in the northeast were potentially
in the path, though at high air mass. An occultation of approximately
100 s was clearly detected after calibrating on a nearby comparison
star (and barely visible on the CCD monitoring screen in real time),
given the relatively cloudy and variable nature of the observing
conditions. We used the observation to refine the prediction model that
is crucial for the 23/27 June occultations of Pluto-Charon/Pluto-Hydra,
respectively. Observations in clear conditions with the Magdalena
Ridge Observatory's 2.4-m telescope in New Mexico and another of our
POETS did not show an occultation to better than 1%. This nondetection
provides a constraint for a Pluto atmospheric graze or the potential
shift of the path of Charon sufficiently far north to that site from
the predicted path in northernmost South America.
---------------------------------------------------------
Title: Is the Sunspot Cycle About to Stop?
Authors: Pasachoff, Jay; MacRobert, Alan M.
2011S&T...122c..12P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Astronomy: Supernova century
Authors: Pasachoff, Jay M.
2011Natur.476..280P Altcode:
Jay Pasachoff relishes a novel that brings to life the scientific
stars of the 1600s.
---------------------------------------------------------
Title: The U.S. Eclipse Megamovie in 2017: a white paper on a unique
outreach event
Authors: Hudson, Hugh S.; McIntosh, Scott W.; Habbal, Shadia R.;
Pasachoff, Jay M.; Peticolas, Laura
2011arXiv1108.3486H Altcode:
Totality during the solar eclipse of 2017 traverses the entire breadth
of the continental United States, from Oregon to South Carolina. It thus
provides the opportunity to assemble a very large number of images,
obtained by amateur observers all along the path, into a continuous
record of coronal evolution in time; totality lasts for an hour and
a half over the continental U.S. While we describe this event here as
an opportunity for public education and outreach, such a movie -with
very high time resolution and extending to the chromosphere - will also
contain unprecedented information about the physics of the solar corona.
---------------------------------------------------------
Title: The Solar System in the Age of Space Exploration
Authors: Pasachoff, Jay M.
2011mtpr.conf....3P Altcode:
We are celebrating the 50th anniversary of the launch of Sputnik, which
began the space age. Though the manned exploration of the solar system
has been limited to the Moon, in NASA's Apollo Program that ended over
35 years ago, robotic exploration of the solar system continues to be
very successful. This paper explores the latest space mission and other
observations of each planet and of each type of solar-system object,
including dwarf planets, asteroids, and comets, as well as the sun.
---------------------------------------------------------
Title: Structure and Dynamics of the 2010 July 11 Eclipse White-light
Corona
Authors: Pasachoff, J. M.; Rušin, V.; Druckmüllerová, H.; Saniga,
M.; Lu, M.; Malamut, C.; Seaton, D. B.; Golub, L.; Engell, A. J.;
Hill, S. W.; Lucas, R.
2011ApJ...734..114P Altcode:
The white-light corona (WLC) during the total solar eclipse on 2010
July 11 was observed by several teams in the Moon's shadow stretching
across the Pacific Ocean and a number of isolated islands. We present
a comparison of the WLC as observed by eclipse teams located on the
Tatakoto Atoll in French Polynesia and on Easter Island, 83 minutes
later, combined with near-simultaneous space observations. The eclipse
was observed at the beginning of the solar cycle, not long after solar
minimum. Nevertheless, the solar corona shows a plethora of different
features (coronal holes, helmet streamers, polar rays, very faint
loops and radial-oriented thin streamers, a coronal mass ejection,
and a puzzling "curtain-like" object above the north pole). Comparing
the observations from the two sites enables us to detect some dynamic
phenomena. The eclipse observations are further compared with a
hairy-ball model of the magnetic field and near-simultaneous images from
the Atmospheric Imaging Assembly on NASA's Solar Dynamics Observatory,
the Extreme Ultraviolet Imager on NASA's Solar Terrestrial Relations
Observatory, the Sun Watcher, using Active Pixel System Detector and
Image Processing on ESA's PRoject for Onboard Autonomy, and the Naval
Research Laboratory's Large Angle and Spectrometric Coronagraph on
ESA's Solar and Heliospheric Observatory. The Ludendorff flattening
coefficient is 0.156, matching the expected ellipticity of coronal
isophotes at 2 R <SUB>sun</SUB>, for this rising phase of the
solar-activity cycle.
---------------------------------------------------------
Title: Blinded by the Light: Solar Eclipses in Art-Science, Symbolism,
and Spectacle
Authors: Olson, R. J. M.; Pasachoff, J. M.
2011ASPC..441..205O Altcode:
After a short discussion of the history of astronomical
representations-beginning with Giotto's Scrovegni Chapel-this paper
briefly surveys highlights of solar eclipses portrayed by western
artists, considering the impact of astronomical discoveries on them.
---------------------------------------------------------
Title: Attempted Stellar-Occultation Observations for KBO (20000)
Varuna on 10 February 2011
Authors: Pasachoff, Jay M.; Babcock, B. A.; Elliot, J. L.; Person,
M. J.; Gulbis, A. A. S.; Zuluaga, C.; Zangari, A.; Rosing, W.; Bianco,
F. B.; Ciotti, J. E.; Kessler, M. R.; Plunkett, S. W. L., Jr.; Hiraoka,
N. D.; Mohanan, K.; Pilger, E.; George, T.; Breit, D.; Preston, S.;
Lonergan, K.; Menaker, S.; Egger, J.; Lockhart, M.; Gutoski, M.;
Rulon, P.; Hampton, D.; Jiang, X.; Bai, J.; Chen, W. P.; Lehner, M.;
Wang, J. H.; Zhang, Z. W.; Tokimasa, N.
2011AAS...21822411P Altcode: 2011BAAS..43G22411P
We attempted to observe the 10 February 2011 occultation of a star
of UCAC2 magnitude 15.5 by the Kuiper-belt object (20000) Varuna
(visual magnitude 20.2), to determine its size, albedo, and other
basic properties. Our original predictions showed the path going
between Hawaii and Alaska, but SMARTS astrometry a month before the
event moved the prediction 1,646 km north, so we added sites in the
northwestern continental US and Alaska. We had clear weather at
several sites in the predicted path (Alaska, Pacific Northwest),
another site in the 1-sigma path (California), and several sites
near the 3-sigma path (Hawaii, China, Taiwan, Japan), though
no occultation was detected. Clouds or other problems prevented
observations at several other sites. The appulse observations will
be used to improve the ephemeris for future Varuna observations. See
http://occult.mit.edu/research/occultations/kbo/Varuna/Varuna.20110210/index.html
and stellaroccultations.info. <P />This work was supported, in part,
by grants NNX10AB27G to MIT and NNX08AO50G to Williams College from
NASA's Planetary Astronomy Division. We thank Don Hampton of the Poker
Flat Research Range, Alaska, for his assistance.
---------------------------------------------------------
Title: The Solar Corona and a CME at the 2010 Total Eclipse
Authors: Pasachoff, Jay M.; Rusin, V.; Druckmüllerová, H.; Saniga,
M.; Lu, M.; Malamut, C.; Seaton, D. B.; Golub, L.; Engell, A. J.;
Hill, S. W.; Lucas, R.
2011SPD....42.1813P Altcode: 2011BAAS..43S.1813P
The 11 July 2010 total solar eclipse was observed on the ground
from French Polynesia and, 83 minutes later, from Easter Island, and
near-simultaneous images were made with spacecraft instruments including
AIA/SDO, HMI/SDO, EUVI/STEREO, SWAP/PROBA2, EIT/SOHO, and LASCO/SOHO. We
report on changes in the corona detectable with high-resolution image
processing of the ground-based eclipse coronal imaging, including
two CME's that were seen to evolve. We compare with the spacecraft
images to give a complete depiction of coronal structure at the time
of the eclipse, which corresponded to a low but rising phase of the
solar-activity cycle. <P />We acknowledge the support of NASA's MSFC
NNX10AK47A, NSF REU AST-1005024 with DoD ASSURE, VEGA 2/0098/10 of the
Slovak Acad. Sci, 205/09/1469 of the Czech Science Foundation, PRODEX
C90345 of ESA/BELSPO, FP7/2007-2013/218816 SOTERIA, Lockheed Martin;
for equipment: Nikon Professional Services, ASTELCO Systems GmbH
(Germany), and National Geographic Society's Photographic Division;
and colleagues Y.-M. Wang (NRL), S. Habbal (U. Hawaii), H. Lanteires
(Tatakoto), and J. Kern (Carnegie Obs.).
---------------------------------------------------------
Title: Music for Dwarf Planets
Authors: Pasachoff, Jay
2011S&T...121d..10P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: High-resolution Satellite Imaging of the 2004 Transit of
Venus and Asymmetries in the Cytherean Atmosphere
Authors: Pasachoff, Jay M.; Schneider, Glenn; Widemann, Thomas
2011AJ....141..112P Altcode:
This paper presents the only space-borne optical-imaging observations
of the 2004 June 8 transit of Venus, the first such transit visible from
Earth since AD 1882. The high-resolution, high-cadence satellite images
we arranged from NASA's Transition Region and Coronal Explorer (TRACE)
reveal the onset of visibility of Venus's atmosphere and give further
information about the black-drop effect, whose causes we previously
demonstrated from TRACE observations of a transit of Mercury. The
atmosphere is gradually revealed before second contact and after
third contact, resulting from the changing depth of atmospheric layers
refracting the photospheric surface into the observer's direction. We
use Venus Express observations to relate the atmospheric arcs seen
during the transit to the atmospheric structure of Venus. Finally, we
relate the transit images to current and future exoplanet observations,
providing a sort of ground truth showing an analog in our solar system
to effects observable only with light curves in other solar systems
with the Kepler and CoRoT missions and ground-based exoplanet-transit
observations.
---------------------------------------------------------
Title: A Search for Satellites of Kuiper Belt Object 55636 from the
2009 October 9 Occultation
Authors: Jensen-Clem, Rebecca; Elliot, J. L.; Person, M. J.; Zuluaga,
C. A.; Bosh, A. S.; Adams, E. R.; Brothers, T. C.; Gulbis, A. A. S.;
Levine, S. E.; Lockhart, M.; Zangari, A. M.; Babcock, B. A.; DuPre, K.;
Pasachoff, J. M.; Souza, S. P.; Rosing, W.; Secrest, N.; Bright, L.;
Dunham, E. W.; Kakkala, M.; Tilleman, T.; Rapoport, S.; Zambrano-Marin,
L.; Wolf, J.; Morzinski, K.
2011AAS...21730605J Altcode: 2011BAAS...4330605J
A world-wide observing campaign of 21 telescopes at 18 sites was
organized by Elliot et al. (2010 Nature 465, 897) to observe the 2009
Oct. 9 stellar occultation of 2UCAC 41650964 (UCAC2 magnitude 13.1)
by the Kuiper Belt object 55636 (visual magnitude 19.6). Integration
times varied between 0.05 seconds at the Vatican Advanced Technology
Telescope and 5 seconds at Mauna Kea mid-level. Data from the two sites
that successfully observed the occultation (Haleakala and the Mauna
Kea mid-level) were analyzed by Elliot et al. (2010) to determine the
diameter and albedo of 55636. In this study, we use the entire data
set to search for signatures of occultations by nearby satellites. One
satellite previously discovered with occultation data is Neptune's
moon Larissa, which was detected during Neptune's close approach to a
star in 1982 (Reitsema et al. 1982). No satellites are found in this
study, and upper limits will be reported on satellite radii within
the volume probed (2 x 10<SUP>-8</SUP> of the Hill Sphere). This work
was supported, in part, by NASA Grants NNX10AB27G (MIT), NNX08AO50G
(Williams College), and NNH08AI17I (USNO-FS) and NSF Grant AST-0406493
(MIT). Student participation was supported in part by NSF's REU program
and NASA's Massachusetts Space Grant.
---------------------------------------------------------
Title: Simultaneous Observations of the Chromosphere with TRACE
and SUMER
Authors: Pasachoff, Jay M.; Tingle, Evan D.; Dammasch, Ingolf E.;
Sterling, Alphonse C.
2011SoPh..268..151P Altcode: 2010SoPh..tmp..209P; 2010SoPh..tmp..233P; 2010arXiv1010.4814P
Using mainly the 1600 Å continuum channel and also the 1216 Å Lyman-α
channel (which includes some UV continuum and C IV emission) aboard
the TRACE satellite, we observed the complete lifetime of a transient,
bright chromospheric loop. Simultaneous observations with the SUMER
instrument aboard the SOHO spacecraft revealed interesting material
velocities through the Doppler effect existing above the chromospheric
loop imaged with TRACE, possibly corresponding to extended nonvisible
loops, or the base of an X-ray jet.
---------------------------------------------------------
Title: Report of Some Comets: The Discovery of Uranus and Comets by
William, Caroline, and John Herschel
Authors: Pasachoff, Jay M.; Olson, R. J. M.
2011AAS...21711101P Altcode: 2011BAAS...4311101P
We report on the discovery and drawings of comets by William, Caroline,
and John Herschel. The first discovery, by William Herschel, in 1781
from Bath, published in the Philosophical Transactions of the Royal
Society with the title "Report of a Comet," turned out to be Uranus,
the first planet ever discovered, Mercury through Saturn having been
known since antiquity. William's sister Caroline was given duties of
sweeping the skies and turned out to be a discoverer of 8 comets in her
own right, in addition to keeping William's notes. Caroline's comets
were discovered from Slough between 1786 and 1797. In the process,
we also discuss original documents from the archives of the Royal
Society and of the Royal Astronomical Society. We conclude by showing
comet drawings that we have recently attributed to John Herschel,
including Halley's Comet from 1836, recently located in the Ransom
Center of the University of Texas at Austin. <P />Acknowledgments:
Planetary astronomy at Williams College is supported in part by grant
NNX08AO50G from NASA Planetary Astronomy. We thank Peter Hingley of
the Royal Astronomical Society and Richard Oram of the Harry Ransom
Center of The University of Texas at Austin for their assistance.
---------------------------------------------------------
Title: The Making of History's Greatest Star Map and A Grand and
Bold Thing: An Extraordinary New Map of the Universe Ushering in a
New Era of Discovery
Authors: Perryman, Michael; Finkbeiner, Ann; Pasachoff, Jay M.
2011PhT....64e..45P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Pluto's Atmosphere from the July 2010 Stellar Occultation
Authors: Person, Michael J.; Elliot, J. L.; Bosh, A. S.; Gulbis,
A. A. S.; Jensen-Clem, R.; Lockhart, M. F.; Zangari, A. M.; Zuluaga,
C. A.; Levine, S. E.; Pasachoff, J. M.; Souza, S. P.; Lu, M.; Malamut,
C.; Rojo, P.; Bailyn, C. D.; MacDonald, R. K. D.; Ivarsen, K. M.;
Reichart, D. E.; LaCluyze, A. P.; Nysewander, M. C.; Haislip, J. B.
2010DPS....42.2003P Altcode: 2010BAAS...42R.983P
We have observed the 4 July 2010 stellar occultation by Pluto as part
of our program of monitoring Pluto's atmospheric changes over the
last decade. Successful observations were obtained from three sites:
Cerro Calan and Cerro Tololo, Chile, as well as the HESS-project site
(High Energy Stereoscopic System) in southwestern Namibia. Successful
telescope apertures ranged from 0.45 m to 1.0 m and resulted in
seven occultation light curves for the event from among the three
sites. Simultaneous analysis of the seven light curves indicates
that Pluto's atmosphere continues to be stable, as the calculated
atmospheric radii are consistent with those detected in 2006 (Elliot
et al., AJ 134, 1, 2007) and 2007 (Person et al., AJ 136, 1510, 2008),
continuing the stability that followed the large pressure increase
detected between 1988 (Millis et al., Icarus 105, 282, 1993) and 2002
(Elliot et al., Nature 424, 165, 2003). We will present the overall
astrometric solution as well as current profiles for Pluto's upper
atmospheric temperature and pressure obtained from inversion of the
light curves (Elliot, Person, and Qu, AJ 126, 1041, 2003). <P />This
work was supported, in part, by grants NNX10AB27G to MIT, NNX08AO50G
to Williams College, and NNH08AI17I to the USNO from NASA's Planetary
Astronomy Division. The 0.75-m ATOM (Automatic Telescope for Optical
Monitoring) light curve was obtained with the generous assistance of
the HESS-project staff, arranged by Stefan Wagner and Marcus Hauser
of the University of Heidelberg. The 0.45-m Goto telescope at Cerro
Calán National Astronomical Observatory, Universidad de Chile, was
donated by the Government of Japan. PROMPT (Panchromatic Robotic Optical
Monitoring and Polarimetry Telescopes) observations at Cerro Tololo
were made possible by the Robert Martin Ayers Science Fund. Student
participation was supported in part by NSF's REU program and NASA's
Massachusetts Space Grant.
---------------------------------------------------------
Title: The 3/4 July 2010 Pluto Stellar-Occultation Observations
Authors: Pasachoff, Jay M.; Elliot, J. L.; Souza, S. P.; Person, M. J.;
Zuluaga, C.; Bosh, A. S.; Zangari, A. M.; Jensen-Clem, R.; Lockhart,
M.; Gulbis, A. A. S.; Rojo, P.; Lu, M.; Malamut, C.; Levine, S. E.;
Ivarsen, K. M.; Reichart, D. E.; LaCluyze, A. P.; Nysewander, M. C.;
Haislip, J. B.; MacDonald, R. K. D.; Bailyn, C. D.; Emilio, M.; Jehin,
E.; Gillon, M.; Manfroid, J.; Chantry, V.; Magain, P.; Hutsemekers,
D.; Queloz, D.
2010DPS....42.2002P Altcode: 2010BAAS...42Q.983P
Continuing our monitoring of Pluto's atmospheric temperature and
pressure, previously shown by us to be increasing (Elliot et al.,
Nature 424, 165, 2003; Pasachoff et al., AJ 129, 1718, 2005)
and subsequently found by us to be leveling off (Elliot et al.,
AJ 134, 1, 2007), we report on a stellar occultation by Pluto of
UCAC2 mag=15.3, observed from South America and Africa on 4 July
2010 UT. Success was achieved with a 0.45 m at Cerro Calan using
one of our POETS (Portable Occultation, Eclipse, and Transit System;
Souza et al. PASP 118, 1550, 2006), a 1.0 SMARTS (Small and Medium
Aperture Research Telescope System) at Cerro Tololo, four 0.6 m
telescopes of PROMPT (Panchromatic Robotic Optical Monitoring and
Polarimetry Telescopes) on Cerro Tololo, and TRAPPIST's (TRansiting
Planets and Planetesimals Small Telescope) 0.6-m telescope on La
Silla in Chile; the 0.35 m telescope of U. Ponta Grossa, Brazil;
and the 0.75-m ATOM (Automatic Telescope for Optical Monitoring),
Namibia, using POETS. Winds prevented opening the 6.5 m Magellan/Clay
telescope on Las Campanas, Chile, with its own frame-transfer camera,
and clouds obscured the 1.9 m telescope at Sutherland, South Africa,
which had POETS. With shadow velocity 23.6 km/s, it was a rapid event:
maximum occultation <2 minutes. <P />The observations were supported
in part by grants NNX08AO50G to Williams College and NNX10AB27G to
MIT from NASA's Planetary Astronomy Division, and NNH08AI17I to USNO
for astrometry. Student participation was supported in part by NASA's
Massachusetts Space Grant and NSF's REU. Japan's government donated
U. Chile's Cerro Calan Goto telescope. PROMPT observations were made
possible by the Robert Martin Ayers Science Fund. TRAPPIST is a project
driven by the University of Liège, in close collaboration with the
Observatory of Geneva, supported by the Belgian Fund for Scientific
Research and the Swiss National Science Foundation.
---------------------------------------------------------
Title: Size and Albedo of the Kuiper Belt Object 55636
Authors: Elliot, James L.; Person, M. J.; Zuluaga, C. A.; Bosh,
A. S.; Adams, E. R.; Brothers, T. C.; Gulbis, A. A. S.; Levine, S. E.;
Lockhart, M.; Zangari, A. M.; Babcock, B. A.; DuPré, K.; Pasachoff,
J. M.; Souza, S. P.; Rosing, W.; Secrest, N.
2010DPS....42.2302E Altcode: 2010BAAS...42..991E
Due to the small sizes and great distances of Kuiper belt objects
(KBOs), it is difficult to determine their diameters. We report
multi-chord observations of a KBO stellar occultation, which occurred
on 2009 October 9 (Elliot, J. L., et al. 2010, Nature, 465, 897). We
set up a network of 21 telescopes at 18 stations, spanning a distance
of 5920 km perpendicular to the predicted shadow path for the 2009
October 9 stellar occultation by the KBO 55636. Of these stations,
seven could not observe due to weather, nine reported non-detections,
and two observed an occultation, both in Hawai'i: the 2.0-m Faulkes
North telescope at Haleakala and a 0.36-m portable telescope at the
Visitor Information Station at the Onizuka Center for International
Astronomy on Mauna Kea (located at the Mauna Kea Mid Level). We find
that 55636 (2002 TX300), which is a member of the water-ice rich Haumea
KBO collisional family (Brown, M. E., et al. 2007, Nature, 446, 294),
has a mean radius of 143 ± 5 km (for a circular solution). Allowing
for possible elliptical shapes we find a geometric albedo of 0.88
+0.15/-0.06 in the V photometric band. This firmly establishes that
55636 is smaller than previously thought and like its parent body,
Haumea, is among the most highly reflective objects in the Solar
System. Dynamical calculations by two groups indicate that the
collision that created 55636 occurred at least 1 Gyr ago (Ragozzine,
D., & Brown, M. E. 2007, AJ, 134, 2160; Schlichting, H. E., &
Sari, R. 2009, ApJ, 700, 1242), which implies either that 55636 has
an active resurfacing mechanism, or that fresh water ice in the outer
solar system can persist for Gyr timescales. This work was supported,
in part by NASA Grants NNX10AB27G (MIT), NNX08AO50G (Williams College),
and NNH08AI17I (USNO-FS).
---------------------------------------------------------
Title: Solar Eclipses for Science and for Public Education
Authors: Pasachoff, Jay
2010AIPC.1283...40P Altcode:
On the rare occurrences of total solar eclipses, about 350 years
apart at a given terrestrial location and 18 months apart in the
world, people in the zone of totality are dazzled and impressed by the
spectacular phenomena that become visible in the midst of atmospheric
darkening. I describe a selection of scientific results about the
solar chromosphere corona that are obtained at eclipses, from the
historic discovery of helium to present-day investigations of how the
corona gets to be 2,000,000 K. I also describe how the attention to the
eclipse, to astronomy, and to science in general that often accompanies
eclipse day in not only the zone of totality but also to thousands
of kilometers to either side, can lead to teaching opportunities not
only for students participating in the scientific observing but also
to all students and the general public.
---------------------------------------------------------
Title: Pluto and Beyond: Stellar-Occultation Web Pages for Education
and Observation Planning
Authors: Pasachoff, Jay M.; Brown, M. E.; Person, M. J.; Tam, Y. H. Ng
2010DPS....42.0701P Altcode: 2010BAAS...42..953P
The method of stellar occultation is a powerful way to investigate
objects in the outer solar system, including their sizes, their
shapes, their atmospheres, and, when present, rings. Following series
of observations of outer-solar-system objects, including the dwarf
planets Pluto and Haumea, satellites Charon and Nix, additional
Kuiper-belt object 55636, and Triton, we have prepared web pages
at Williams College describing the results and linking published
papers and meeting abstracts as well as light curves, images, and
expedition photographs. Brown's pages at Caltech (www.gps.caltech.edu/
mbrown/2003EL61/) discuss the mutual occultation and transit events
of Haumea and its moon Namaka, showing predictions over the last
couple of years, though no observations of the mutual events (from
the Hale 5-m telescope at the Palomar Observatory on down) have yet
been successful. This paper will include Haumea/Namaka predictions
for the coming observation season. The MIT Planetary Astronomy
Lab's web pages (occult.mit.edu) are more technical in nature,
providing information useful for planning observations, which are
usually made simultaneously with multiple telescopes to provide
a variety of chords across the objects. For overall access to our
occultation information, go to http://www.stellaroccultations.info
or http://www.williams.edu/Astronomy/research/occultations. <P
/>Observations have been supported in part by grants NNX08AO50G to
Williams College, NNX10AB27G to MIT, and NNG05GI02G to Caltech from
NASA's Planetary Astronomy Division. Student participation was supported
in part by NASA's Massachusetts Space Grant.
---------------------------------------------------------
Title: Tales of Meteors I
Authors: Olson, Roberta M. J.; Pasachoff, Jay M.
2010S&T...120c...8O Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Resource Letter SPh-1: Solar Physics
Authors: Pasachoff, Jay M.
2010AmJPh..78..890P Altcode:
This Resource Letter provides a guide to printed literature, listing
selected books and articles and online resources about scientific
and cultural references to the Sun and the related topics of solar
spectroscopy and space weather. Topics include helioseismology,
the chromosphere and corona at solar eclipses, sunspots and other
solar activity, and total solar irradiance, as well as instrumental
references including spectroheliographs, coelostats, and observatories
on the ground and in space. References to general works on heliophysics
and plasma physics are minimized.
---------------------------------------------------------
Title: The origin and diffusion of the H and K notation
Authors: Pasachoff, Jay M.; Suer, Terry-Ann
2010JAHH...13..120P Altcode:
Though many or most astronomers and astronomy students may think
that H and K, as in the Ca II ‘H and K lines’, were named by
Fraunhofer, actually only the H line was in Fraunhofer's original
notation. He also used ‘I’ to indicate the end of the spectrum in
his widely-reproduced 1814 drawing, of which an engraved version was
published in 1817. We have searched references from nineteenth-century
books and journals to find the first use of ‘K’ to indicate the
ionized-calcium spectral line at 393.3 nm and located the probable
first use and eventually the reuse of the notation.
---------------------------------------------------------
Title: A Comparison of the Red and Green Coronal Line Intensities
at the 29 March 2006 and the 1 August 2008 Total Solar Eclipses:
Considerations of the Temperature of the Solar Corona
Authors: Voulgaris, A.; Athanasiadis, T.; Seiradakis, J. H.; Pasachoff,
J. M.
2010SoPh..264...45V Altcode: 2010SoPh..tmp...98V; 2009arXiv0911.0325V
During the total solar eclipse at Akademgorodok, Siberia, Russia,
on 1 August 2008, we imaged the flash spectrum with a slitless
spectrograph. We have spectroscopically determined the duration of
totality, the epoch of the second and third contacts and the duration
of the flash spectrum. Here we compare the 2008 flash spectra with
those that we similarly obtained from the total solar eclipse of 29
March 2006, at Kastellorizo, Greece. Any changes of the intensity
of the coronal emission lines, in particularly those of Fe X and Fe
XIV, could give us valuable information about the temperature of the
corona. The results show that the ionization state of the corona,
as manifested especially by the Fe XIV emission line, was much weaker
during the 2008 eclipse, indicating that following the long, inactive
period during the solar minimum, there was a drop in the overall
temperature of the solar corona.
---------------------------------------------------------
Title: Size and albedo of Kuiper belt object 55636 from a stellar
occultation
Authors: Elliot, J. L.; Person, M. J.; Zuluaga, C. A.; Bosh, A. S.;
Adams, E. R.; Brothers, T. C.; Gulbis, A. A. S.; Levine, S. E.;
Lockhart, M.; Zangari, A. M.; Babcock, B. A.; Dupré, K.; Pasachoff,
J. M.; Souza, S. P.; Rosing, W.; Secrest, N.; Bright, L.; Dunham,
E. W.; Sheppard, S. S.; Kakkala, M.; Tilleman, T.; Berger, B.; Briggs,
J. W.; Jacobson, G.; Valleli, P.; Volz, B.; Rapoport, S.; Hart, R.;
Brucker, M.; Michel, R.; Mattingly, A.; Zambrano-Marin, L.; Meyer,
A. W.; Wolf, J.; Ryan, E. V.; Ryan, W. H.; Morzinski, K.; Grigsby,
B.; Brimacombe, J.; Ragozzine, D.; Montano, H. G.; Gilmore, A.
2010Natur.465..897E Altcode:
The Kuiper belt is a collection of small bodies (Kuiper belt objects,
KBOs) that lie beyond the orbit of Neptune and which are believed
to have formed contemporaneously with the planets. Their small
size and great distance make them difficult to study. KBO 55636
(2002 TX<SUB>300</SUB>) is a member of the water-ice-rich Haumea
KBO collisional family. The Haumea family are among the most highly
reflective objects in the Solar System. Dynamical calculations indicate
that the collision that created KBO 55636 occurred at least 1Gyr
ago. Here we report observations of a multi-chord stellar occultation
by KBO 55636, which occurred on 9 October 2009 UT. We find that it has
a mean radius of 143+/-5km (assuming a circular solution). Allowing
for possible elliptical shapes, we find a geometric albedo of
0.88<SUB>-0.06</SUB><SUP>+0.15</SUP> in the V photometric band, which
establishes that KBO 55636 is smaller than previously thought and that,
like its parent body, it is highly reflective. The dynamical age implies
either that KBO 55636 has an active resurfacing mechanism, or that fresh
water-ice in the outer Solar System can persist for gigayear timescales.
---------------------------------------------------------
Title: Commission 46: Astronomy Education and Development
Authors: Stavinschi, Magda D.; Ros, Rosa M.; Pasachoff, Jay M.;
Andersen, Johannes; Deustua, Susana; De Greve, Jean-Pierre; Guinan,
Edward F.; Haubold, Hans J.; Earnshaw, John B.; Jones, Barrie W.;
Kochhar, Rajesh K.; Leung, Kam-Ching; Marschall, Laurence A.; Percy,
John R.; Torres-Peimbert, Silvia
2010IAUTB..27..270S Altcode:
Commission 46 had held two sessions of business meetings during the
General Assembly in Rio de Janeiro. Both of them were chaired by
Magda Stavinschi.
---------------------------------------------------------
Title: Search for 1-Hz Coronal-Loop Oscillations at the 2008 and
2009 Total Eclipses
Authors: Pasachoff, Jay M.; Babcock, B. A.; DuPré, K.; Kern, J.;
Nesterenko, A.; Nesterenko, I.
2010AAS...21640716P Altcode: 2010BAAS...41..862P
We report observations through narrow-band filters at total
solar eclipses at high cadence to search for Fourier power 1 Hz, a
prediction of certain classes of coronal heating through MHD waves,
such as surface Alfvén waves. We previous reported such power at the
1999 eclipse (Pasachoff, Babcock, Russell, Seaton, Solar Phys. 207,
241-257, 2002). We observed at 10 Hz for 2 min 20 sec in Siberia in
2008 with the coronal red line at 637.4 nm and the coronal green line
at 530.3 nm, and at 6 Hz for 5 min 50 sec at Tianhuangping, China, in
2009 with the coronal green line and a nearby continuum, using 20-cm
telescopes. The sky was clear in 2008 while the eclipse was observed
through moving clouds in 2009. The weakening corona gave few features
on which to make a fine alignment, and much time has been spent on
details of aligning the series of images. We report on the status
of the alignment and the resulting transforms, and place the results
in the context of the solar-activity cycle, which we show through a
series of radial-filter images made as part of our expeditions in 1999,
2001, 2006, 2008, and 2009, spanning the most recent sunspot cycle. <P
/>Acknowledgments: We thank C. Alex Young, Daniel B. Seaton. Yihua Yan,
Jin Zhu, Lin Lan and Chenying Lai. Williams collaborators were Jianjun
Wang, Marek Demianski, Huajai Cao, Sara Dwyer, and Rachel Wagner-Kaiser
in 2009 and Marcus Freeman, William G. Wagner, and Marek Demianski
in 2008. Our expeditions were supported in part by grants from the
Committee for Research and Exploration of the National Geographic
Society. We thank the NSF Heliospheric Program for 2006 suppport and
the Planetary Astronomy division of NASA for imaging-system support.
---------------------------------------------------------
Title: The Galactic deuterium gradient
Authors: Lubowich, Donald; Pasachoff, Jay M.
2010IAUS..268..179L Altcode:
The Galactic deuterium abundance gradient has been determined from
observations of DCN in Galactic molecular clouds. This is the only
way to observe D throughout the Galaxy because the molecular clouds
are not limited to the 2 kpc region around the Sun observed with FUSE
and from DI. We used an astrochemistry model and the DCN/HCN ratios to
estimate the underlying D/H ratios in 16 molecular clouds including five
in the Galactic Center. The resulting positive Galactic D gradient and
reduced Galactic Center D/H ratio imply that there are no significant
Galactic sources of D, there is continuous infall of low-metallicity
gas into the Galaxy, and that deuterium is cosmological.
---------------------------------------------------------
Title: The Origin and Diffusion of the H and K Notation
Authors: Pasachoff, Jay M.; Suer, T. A.
2010AAS...21530403P Altcode: 2010BAAS...42..301P
Though many or most astronomers and astronomy students may think that
H and K, as in the Ca II "H and K lines," were named by Fraunhofer,
actually only the H line was in Fraunhofer's original notation. He also
used "I" to indicate the end of the spectrum in his widely reproduced
1814 drawing, published in 1817. We have searched references from
19th-century books and journals to find the first use of "K" to indicate
the ionized-calcium spectral line at 383.3 nm and located the probable
first use and eventually the reuse of the notation.
---------------------------------------------------------
Title: Coronal Observations at the Siberian 2008 Total Solar Eclipse
Authors: Pasachoff, Jay M.; Babcock, B. A.; Freeman, M. J.; DuPré,
K. M.; Demianski, M.; Nesterenko, A.; Nesterenko, I.; Schneider, G.
2009AAS...21360003P Altcode:
We successfully observed the 1 August 2008 total solar eclipse from
the rooftop observatory of the State University of Novosibirsk in
Akademgorodok, Siberia, latitude 55° N at 10:45 UT in clear skies
and also from an airplane at 83° N latitude north of Svalbard at 9:43
UT. Our prime experiment in Akademgorodok was a set of high-cadence,
10 Hz, observations in the coronal green line at 530.3 nm from [Fe
XIV] to verify and extend our previous findings of excess power in
the 0.5 Hz to 1 Hz region as predicted by a subset of coronal-heating
theories. We used twin 0.2-m telescopes with narrow-band interference
filters and our POETS frame-transfer CCD's on the university's Paramount
ME. Additional photography included graded-exposure sets of images
meant for post-processing to compare with images taken earlier from the
airplane and later from the ground in Mongolia and China to provide
time differences of over 90 minutes. We also obtained HD video. Our
comparison of the images from the airplane and from Siberia will be
used to search for coronal motions.
---------------------------------------------------------
Title: Attempted Observations of the 2009 Occultation of a Star by Nix
Authors: Pasachoff, Jay M.; Widemann, T.; Sicardy, B.; Lister, T.;
Tholen, D. J.; Gulbis, A. A. S.; Adams, E. R.
2009AAS...21460601P Altcode:
We attempted to observe the predicted 4 March 2009, 13:56 UT,
approximately 6-second-long occultation of an 11th magnitude star
by Pluto's small moon Nix, which is fainter than 23rd magnitude. In
parallel starlight, the path was 88 km in width with a one-sigma
range from 44 km to 110 km. The Tycho star is at 18 12 09.86 17 42 03.3
(J2000.0), and has R=11.8 and K=10.4. The occultation path was predicted
to cross the Hawaiian islands, with a southern boundary cutting through
Maui and missing the telescopes on Mauna Kea, but the uncertainty in
the prediction (1 sigma) was about 500 km (though only 5 minutes in
time). The path's speed was 15 km/s. In the event, we obtained data
only from the 2-m Faulkes telescope on Maui, with uneven skies. Our
trailed images did not show evidence of the occultation, which would
have dropped the observed intensity at the merged star/Nix position
by about 12 magnitudes or, more likely, if Nix and Pluto were merged
by about 3 magnitudes. Weather prevented observations with MegaCam
on the CFHT, with a MIT POETS on the IRTF, with PanSTARRS on Maui,
as well as with an 0.4-m telescope at Windward Community College on
Oahu. For administrative reasons, we did not succeed in obtaining data
with the 3.7-m AEOS telescope on Maui. In any case, the event was at
low altitude, only 21°, so pointing was at the limits for several of
the telescopes. <P />Our collaboration between Williams College and
MIT is with J. L. Elliot and M. J. Person at MIT and B. A. Babcock
and S. P. Souza at Williams. We thank C. Veillet in Paris, J. Ciotti,
M. Kessler, and G. T. Elliott on Oahu, and L. Young and M. Buie in
Boulder for their collaboration. JMP's work on Pluto is supported in
part by grant NNX08AO50G from NASA's Planetary Science Division and
MIT's by NNX07AN63G.
---------------------------------------------------------
Title: To Boldly Go - Or Not - III
Authors: Pasachoff, Jay M.
2009S&T...118f..10P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Limb Spicules from the Ground and from Space
Authors: Pasachoff, Jay M.; Jacobson, William A.; Sterling, Alphonse C.
2009SoPh..260...59P Altcode: 2009arXiv0909.0027P
We amassed statistics for quiet-sun chromosphere spicules at the limb
using ground-based observations from the Swedish 1-m Solar Telescope on
La Palma and simultaneously from NASA's Transition Region and Coronal
Explorer (TRACE) spacecraft. The observations were obtained in July
2006. With the 0.2 arcsecond resolution obtained after maximizing
the ground-based resolution with the Multi-Object Multi-Frame Blind
Deconvolution (MOMFBD) program, we obtained specific statistics for
sizes and motions of over two dozen individual spicules, based on
movies compiled at 50-second cadence for the series of five wavelengths
observed in a very narrow band at Hα, on-band and at ± 0.035 nm
and ± 0.070 nm (10 s at each wavelength) using the SOUP filter,
and had simultaneous observations in the 160 nm EUV continuum from
TRACE. The MOMFBD restoration also automatically aligned the images,
facilitating the making of Dopplergrams at each off-band pair. We
studied 40 Hα spicules, and 14 EUV spicules that overlapped Hα
spicules; we found that their dynamical and morphological properties
fit into the framework of several previous studies. From a preliminary
comparison with spicule theories, our observations are consistent with
a reconnection mechanism for spicule generation, and with UV spicules
being a sheath region surrounding the Hα spicules.
---------------------------------------------------------
Title: The Solar Corona
Authors: Golub, Leon; Pasachoff, Jay M.
2009soco.book.....G Altcode:
1. Introduction; 2. Brief history of coronal studies; 3. The
coronal spectrum; 4. The solar cycle; 5. Ground-based observations;
6. Observations from space: I. The first 4 decades; 7. Activity of
the inner corona; 8. Observations from space: II. Recent missions;
9. The solar wind; 10. Solar flares and coronal mass ejections; Notes;
References; Index.
---------------------------------------------------------
Title: The MIT Program for Predicting Stellar Occultations by Kuiper
Belt Objects
Authors: Elliot, James L.; Zuluaga, C. A.; Person, M. J.; Adams,
E. R.; Lockhart, M. F.; Zangari, A. M.; Bosh, A. S.; Gulbis, A. A. S.;
Levine, S. E.; Sheppard, S. S.; Dunham, E. W.; Bright, L.; Souza,
S. P.; Pasachoff, J. M.; Babcock, B. A.; Ryan, W. H.; Ryan, E. V.
2009DPS....41.6209E Altcode:
With observations of a stellar occultation by a Kuiper belt object
(KBO) from multiple stations, one could establish its radius with an
accuracy of a few kilometers. Combining this radius with photometry
would establish an accurate geometric albedo. For those KBOs with
orbiting companions, these data will further provide highly accurate
densities constraining material composition. Stellar occultation data
also establish stringent upper limits on any atmospheres and probe for
small, nearby companions. The difficulty in observing a KBO occultation
has been in generating an accurate prediction so that observers can be
deployed within the occultation shadow path. Current KBO ephemerides
are at best accurate to a few tenths of an arcsecond, while angular
radii of the largest bodies are less than 0.02 arcsec. To improve the
ephemerides of the KBOs most promising for stellar occultations, we
conduct astrometric observations of KBOs selected (i) for large angular
radii, and (ii) in sky regions with large star densities. We have made
bi-monthly observations with the Lowell 42-inch Hall telescope since
Dec. 2004 and monthly to bi-monthly observations with the SMARTS 0.9 m
at CTIO since May 2005. Approximately 1200 KBO astrometric measurements
have been submitted to the Minor Planet Center. We use these data to
establish ephemeris correction models with which we predict appulses
by target KBOs. We observed three of these appulses to test our
accuracy. The difference between the predicted and observed closeest
approach agrees within the formal error for two of the three appulses,
but the errors are somewhat larger than the body's radius. Hence our
predictions are almost accurate enough to reliably place observers
within the shadow path of a KBO occultation, and improving with each
astrometric observation. This work is supported, in part, by USRA
subcontract 8500-98-03 (Lowell Observatory) and NASA Grant NNX07AK73G
(MIT).
---------------------------------------------------------
Title: The 2008 August 1 Eclipse Solar-Minimum Corona Unraveled
Authors: Pasachoff, J. M.; Rušin, V.; Druckmüller, M.; Aniol, P.;
Saniga, M.; Minarovjech, M.
2009ApJ...702.1297P Altcode: 2009arXiv0907.1643P
We discuss the results stemming from observations of the white-light and
[Fe XIV] emission corona during the total eclipse of the Sun of 2008
August 1, in Mongolia (Altaj region) and in Russia (Akademgorodok,
Novosibirsk, Siberia). Corresponding to the current extreme solar
minimum, the white-light corona, visible up to 20 solar radii, was of
a transient type with well pronounced helmet streamers situated above a
chain of prominences at position angles 48°, 130°, 241°, and 322°. A
variety of coronal holes, filled with a number of thin polar plumes,
were seen around the poles. Furthering an original method of image
processing, stars up to 12 mag, a Kreutz-group comet (C/2008 O1) and
a coronal mass ejection (CME) were also detected, with the smallest
resolvable structures being of, and at some places even less than, 1
arcsec. Differences, presumably motions, in the corona and prominences
are seen even with the 19 minutes time difference between our sites. In
addition to the high-resolution coronal images, which show the continuum
corona (K-corona) that results from electron scattering of photospheric
light, images of the overlapping green-emission-line (530.3 nm, [Fe
XIV]) corona were obtained with the help of two narrow-passband filters
(centered on the line itself and for the continuum in the vicinity
of 529.1 nm, respectively), each with an FWHM of 0.15 nm. Through
solar observations, on whose scheduling and details we consulted,
with the Solar and Heliospheric Observatory, Hinode's XRT and SOT,
Transition Region and Coronal Explorer, and STEREO, as well as Wilcox
Solar Observatory and Solar and Heliospheric Observatory/Michelson
Doppler Imager magnetograms, we set our eclipse observations in the
context of the current unusually low and prolonged solar minimum.
---------------------------------------------------------
Title: Teaching and Learning Astronomy
Authors: Pasachoff, Jay; Percy, John
2009tla..book.....P Altcode:
Preface; Part I. Astronomy in the Curriculum Around the World:
Preface; 1. Why astronomy is useful and should be included in
the school curriculum John R. Percy; 2. Astronomy and mathematics
education Rosa M. Ros; 3. Astronomy in the curriculum around the
world; 4. Engaging gifted science students through astronomy Robert
Hollow; 5. Poster highlights: astronomy in the curriculum around the
world; Part II. Astronomy Education Research: Preface; 6. Astronomy
education research down under John M. Broadfoot and Ian S. Ginns;
7. A contemporary review of K-16 astronomy education research Janelle
M. Bailey and Timothy F. Slater; 8. Implementing astronomy education
research Leonarda Fucili; 9. The Astronomy Education Review: report on a
new journal Sidney C. Wolff and Andrew Fraknoi; 10. Poster highlights:
astronomy education research; Part III. Educating Students: Preface;
11. Textbooks for K-12 astronomy Jay M. Pasachoff; 12. Distance/internet
astronomy education David H. McKinnon; 13. Educating students with
robotic telescopes - open discussion; 14. Poster highlights - educating
students; Part IV. Educating teachers: Preface; 15. Pre-service
astronomy education of teachers Mary Kay Hemenway; 16. In-service
education of teachers Michèle Gerbaldi; 17. Poster highlights:
educating teachers; Part V. Astronomy and Pseudoscience: Preface;
18. Astronomy, pseudoscience and rational thinking Jayant V. Narlikar;
19. Astronomical pseudosciences in North America John R. Percy and Jay
M. Pasachoff; Part VI. Astronomy and Culture: Preface; 20. Teaching
astronomy in other cultures: archeoastronomy Julieta Fierro; 21. Poster
highlights: astronomy and culture; Part VII. Astronomy in Developing
Countries: Preface; 22. Astronomy Curriculum for developing countries
Case Rijsdijk; 23. Science education resources for the developing
countries James C. White II; Part VIII. Public Outreach in Astronomy:
Preface; 24. What makes informal education programs successful? Nahide
Craig and Isabel Hawkins; 25. The role of science centers and
planetariums Nick Lomb; 26. Science education for the new century -
a European perspective Claus Madsen; 27. Communicating astronomy to
the public Charles Blue; 28. Poster highlights: public outreach in
astronomy; Part IX. The Education Programs of the IAU: Preface; 29. A
short overview of astronomical education carried out by the IAU Syuzo
Isobe; Part X. Discussion; Index.
---------------------------------------------------------
Title: Scientific observations at total solar eclipses
Authors: Pasachoff, Jay M.
2009RAA.....9..613P Altcode:
The occasion of the longest totality of an eclipse in the 18 yr
11⅓ d saros cycle leads to taking stock of the scientific value of
ground-based eclipse observations in this space age. Though a number
of space satellites from the U.S., Europe, Japan, and Russia study the
Sun, scientists at eclipses can observe the solar chromosphere and
corona at higher spatial resolution, at higher temporal resolution,
and at higher spectral resolution than are possible aloft. Furthermore,
eclipse expeditions can transport a wide variety of state-of-the-art
equipment to the path of totality. Thus, for at least some years
to come, solar eclipse observations will remain both scientifically
valuable and cost-effective ways to study the outer solar atmosphere.
---------------------------------------------------------
Title: Solar eclipses as an astrophysical laboratory
Authors: Pasachoff, Jay M.
2009Natur.459..789P Altcode:
Observations of the Sun during total eclipses have led to major
discoveries, such as the existence of helium (from its spectrum),
the high temperature of the corona (though the reason for the high
temperature remains controversial), and the role of magnetic fields
in injecting energy into-and trapping ionized gases within-stellar
atmospheres. A new generation of ground-based eclipse observations
reaches spatial, temporal and spectral-resolution domains that are
inaccessible from space and therefore complement satellite studies.
---------------------------------------------------------
Title: Solar Eclipses and the International Year of Astronomy
Authors: Pasachoff, Jay M.
2009AAS...21440101P Altcode:
Solar eclipses capture the attention of millions of people in the
countries from which they are visible and provide a major opportunity
for public education, in addition to the scientific research and
student training that they provide. The 2009 International Year of
Astronomy began with an annular eclipse visible from Indonesia on 26
January, with partial phases visible also in other parts of southeast
Asia. On 22 July, a major and unusually long total solar eclipse
will begin at dawn in India and travel across China, with almost six
minutes of totality visible near Shanghai and somewhat more visible
from Japanese islands and from ships at sea in the Pacific. Partial
phases will be visible from most of eastern Asia, from mid-Sumatra
and Borneo northward to mid-Siberia. Eclipse activities include many
scientific expeditions and much ecotourism to Shanghai, Hangzhou,
and vicinity. My review article on "Eclipses as an Astrophysical
Laboratory" will appear in Nature as part of their IYA coverage. Our
planetarium presented teacher workshops and we made a film about solar
research. Several new books about the corona or eclipses are appearing
or have appeared. Many articles are appearing in astronomy magazines
and other outlets. Eclipse interviews are appearing on the Planetary
Society's podcast "365 Days of Astronomy" and on National Geographic
Radio. Information about the eclipse and safe observation of the partial
phases are available at http://www.eclipses.info, the Website of the
International Astronomical Union's Working Group on Solar Eclipses and
of its Program Group on Public Education at the Times of Eclipses of
its Commission on Education and Development. <P />The Williams College
Expedition to the 2009 Eclipse in the mountains near Hangzhou, China,
is supported in part by a grant from the Committee for Research and
Exploration of the National Geographic Society. E/PO workshops were
supported by NASA.
---------------------------------------------------------
Title: The X-Ray Environment During the Epoch of Terrestrial Planet
Formation: Chandra Observations of h Persei
Authors: Currie, Thayne; Evans, Nancy Remage; Spitzbart, Brad D.;
Irwin, Jonathan; Wolk, Scott J.; Hernandez, Jesus; Kenyon, Scott J.;
Pasachoff, Jay M.
2009AJ....137.3210C Altcode: 2008arXiv0811.1753C
We describe Chandra/ACIS-I observations of the massive ~ 13-14 Myr-old
cluster, h Persei, part of the famous Double Cluster (h and χ Persei)
in Perseus. Combining the list of Chandra-detected sources with new
optical/IR photometry and optical spectroscopy reveals ~ 165 X-ray
bright stars with V lsim 23. Roughly 142 have optical magnitudes and
colors consistent with cluster membership. The observed distribution
of L<SUB>x</SUB> peaks at L<SUB>x</SUB> ~ 10<SUP>30.3</SUP> erg
s<SUP>-1</SUP> and likely traces the bright edge of a far larger
population of ≈ 0.4-2 M <SUB>sun</SUB> X-ray active stars. From a
short list of X-ray active stars with IRAC 8 μm excess from warm,
terrestrial zone dust, we derive a maximum X-ray flux incident on
forming terrestrial planets. Although there is no correlation between
X-ray activity and IRAC excess, the fractional X-ray luminosity
correlates with optical colors and spectral type. By comparing the
distribution of L<SUB>x</SUB> /L <SUB>sstarf</SUB> versus spectral
type and V - I in h Per with results for other 1-100 Myr-old clusters,
we show that stars slightly more massive than the Sun (gsim 1.5 M
<SUB>sun</SUB>) fall out of X-ray saturation by ≈ 10-15 Myr. Changes
in stellar structure for gsim 1.5 M <SUB>sun</SUB> stars likely play
an important role in this decline of X-ray emission.
---------------------------------------------------------
Title: Pluto Stellar Occultation on 2008 Aug 25
Authors: Buie, Marc W.; Young, L. A.; Young, E. F.; Olkin, C. B.;
Terrell, D.; Parker, J. W.; Durda, D.; Stansberry, J. A.; Reitsema,
H.; French, R. G.; Shoemaker, K.; Brown, M. E.; Schaller, E. L.;
Bauer, J. M.; Young, J. W.; Wasserman, L. H.; Pasachoff, J. M.; Lust,
N.; Fernandez, Y. R.; Dellinger, J. A.; Garossino, P. G. A.; Grigsby,
B.; Stone, R. P. S.; Dillon, W. G.; Mezzalira, F.; Ryan, E. V.; Ryan,
W.; Souza, S. P.; Williams, R.; Sexton, C.
2009DPS....40.4805B Altcode: 2009BAAS...41..562B
We report on a successful occultation of a star by Pluto that was
observable over much of the south and western United States. The
centerline was close to WIRO. We will present seven complete
lightcurves from Crossley/Lick, WIRO, SBO/CU, Palomar, JPL/TMO,
Sierra Stars Obs., and Magdalena Ridge Observatory. We have 2
partial lightcurves from Lowell Obs. and McDonald Obs. where data
loss was caused by clouds. There were attempts at the Steward 90",
George Observatory, and New Mexico Skies that were clouded out. The
UCF station near Orlando was clearly an appulse. A number of other
amateurs also succeeded in collecting data. Our presentation will
provide a final geometric solution for the event as well as baseline
fits to the atmospheric structure. This work was supported by NASA
Planetary Astronomy grants NNX08AO626 and NNX08AO50G.
---------------------------------------------------------
Title: Division XII / Commission 46 / Program Group World-Wide
Development of Astronomy
Authors: Hearnshaw, John B.; Batten, Alan H.; Alsabti, A. Athem;
Fierro, Julieta; Guinan, Edward F.; Kozai, Yoshihide; Levato, Hugo;
Malasan, Hakim L.; Marschall, Laurence A.; Martinez, Peter; Narlikar,
Jayant V.; Osório, J. Pereira; Pasachoff, Jay M.; Perkins, D. Kala;
Zhu, Jin
2009IAUTA..27..429H Altcode:
The Program Group for World-wide Development of Astronomy (PG-WWDA) is
one of nine Commission 46 program groups engaged with various aspects
of astronomical education or development of astronomy education and
research in the developing world. In the case of PG-WWDA, its goals
are to promote astronomy education and research in the developing
world through a variety of activities, including visiting astronomers
in developing countries and interacting with them by way of giving
encouragement and support.
---------------------------------------------------------
Title: Commission 46: Astronomy Education and Development
Authors: Stavinschi, Magdalena G.; Ros, Rosa M.; Pasachoff, Jay M.;
Andersen, Johannes; Deustua, Susana E.; De Greve, Jean-Pierre; Guinan,
Edward F.; Haubold, Hans J.; Hearnshaw, John B.; Jones, Barrie W.;
Kochhar, Rajesh K.; Leung, Kam-Ching; Marschall, Laurence A.; Percy,
John R.; Torres-Peimbert, Silvia
2009IAUTA..27..424S Altcode:
Commission 46 continues its task in the triennium, which started in
September 2006. It seeks to further contribute to the development and
improvement of astronomical education at all levels all over the world
through various projects initiated, maintained and to be developed by
the Commission, and by disseminating information concerning astronomy
education.
---------------------------------------------------------
Title: Comets, Charisma, and Celebrity: Reflections on Their Deep
Impact
Authors: Olson, R. J. M.; Pasachoff, J. M.
2009diwo.conf...41O Altcode:
In celebration of the Deep Impact Mission, this essay explores the
influence of comets on the arts and sciences since the beginning of
recorded time. Through images, ranging from the sublime to the humorous,
it probes the reasons why comets are among the most charismatic visual
spectacles in the universe and why, even as scientific missions unmask
their mysteries, they remain iconic symbols and harbingers of change.
---------------------------------------------------------
Title: Waves in Pluto's Upper Atmosphere
Authors: Person, M. J.; Elliot, J. L.; Gulbis, A. A. S.; Zuluaga,
C. A.; Babcock, B. A.; McKay, A. J.; Pasachoff, J. M.; Souza, S. P.;
Hubbard, W. B.; Kulesa, C. A.; McCarthy, D. W.; Benecchi, S. D.;
Levine, S. E.; Bosh, A. S.; Ryan, E. V.; Ryan, W. H.; Meyer, A.;
Wolf, J.; Hill, J.
2008AJ....136.1510P Altcode:
Observations of the 2007 March 18 occultation of the star P445.3
(2UCAC 25823784; R = 15.3) by Pluto were obtained at high time
resolution at five sites across the western United States and reduced
to produce light curves for each station using standard aperture
photometry. Global models of Pluto's upper atmosphere are fitted
simultaneously to all resulting light curves. The results of these
model fits indicate that the structure of Pluto's upper atmosphere is
essentially unchanged since the previous occultation observed in 2006,
leading to a well-constrained measurement of the atmospheric half-light
radius at 1291 ± 5 km. These results also confirm that the significant
increase in atmospheric pressure detected between 1988 and 2002 has
ceased. Inversion of the Multiple Mirror Telescope Observatory light
curves with unprecedented signal-to-noise ratios reveals significant
oscillations in the number density, pressure, and temperature profiles
of Pluto's atmosphere. Detailed analysis of this highest resolution
light curve indicates that these variations in Pluto's upper atmospheric
structure exhibit a previously unseen oscillatory structure with
strong correlations of features among locations separated by almost
1200 km in Pluto's atmosphere. Thus, we conclude that these variations
are caused by some form of large-scale atmospheric waves. Interpreting
these oscillations as Rossby (planetary) waves allows us to establish an
upper limit of less than 3 m s<SUP>-1</SUP> for horizontal wind speeds
in the sampled region (radius 1340-1460 km) of Pluto's upper atmosphere.
---------------------------------------------------------
Title: Probing small bodies in the outer solar system with stellar
occultations
Authors: Person, M. J.; Elliot, J. L.; Pasachoff, J. M.; Gulbis,
A. A. S.
2008epsc.conf..588P Altcode:
We present a summary of results from the last decade of stellar
occultation studies by members of the MITWilliams consortium. Research
goals included investigations of the atmospheres and figures of small
bodies in the outer solar system, focusing on Triton, Pluto, and
Charon. We concentrated on the prediction, observation, and analysis
of stellar occultations by these bodies. The method of observing
stellar occultations provides higher spatial resolution than any
other Earth-based observing method when examining bodies in the outer
solar system. It also allows for direct measurements of atmospheric
conditions, if any, as the observed starlight is refracted through
the atmospheres of these planetary bodies during the occultation. This
large spatial resolution (about 1 km in the atmosphere of Pluto) and
direct interaction with any atmosphere allows for great sensitivity to
the detailed pressure/temperature structure of a planetary atmosphere,
and multiple observations over several years allow the monitoring of
changes to that structure.
---------------------------------------------------------
Title: Total Solar Irradiance at the 2006 Transit of Mercury and
Application to Transiting-Exoplanet Observations
Authors: Pasachoff, Jay M.; Schneider, G.; Willson, R. C.
2008DPS....40.1119P Altcode: 2008BAAS...40..404P
Following our earlier work on the Total Solar Irradiance (TSI) at
the 2004 transit of Venus, in which an 0.4 percent drop in TSI was
readily detectable with the ACRIM3 instrument on NASA's ACRIMsat,
we report on ACRIM3 observations of the 29 November 2006 transit
of Mercury. We also observed the transit from Haleakala and from
Sacramento Peak. Mercury's cross-sectional angular area is only 1/30th
that of Venus's, so the expected drop in TSI was only 0.01 percent. As
expected, this tiny drop was not detected, though detailed statistical
analysis continues. Our Venus and Mercury transit observations provide
closeup views of phenomena increasingly observed for exoplanets and
provide examples by which one can assess the limits at which exoplanet
discoveries can be made with the transit method. <P />Acknowledgments:
JMP's planetary occultation work and the POETS instrument (Portable
Occultation, Eclipse, and Transit System) were funded in part by NASA
Planetary Astronomy grants NNG04GE48G, NNG04GF25G, NNH04ZSS001N,
and NNG05GG75G to M.I.T. and Williams College, and continues under
NNX08AO50G. Our transit work was funded in part by the Committee for
Research and Exploration of the National Geographic Society. ACRIMsat
is supported by a grant from NASA to Columbia University.
---------------------------------------------------------
Title: Observations and Chemical Modelling of Edge Cloud 2
Authors: Ruffle, P. M. E.; Millar, T. J.; Roberts, H.; Lubowich,
D. A.; Henkel, C.; Pasachoff, J. M.; Brammer, G.
2008ASPC..395..377R Altcode:
Edge Cloud 2 (EC2) is a large molecular cloud with one of the largest
galactocentric distances known in the Milky Way (R<SUB>gc</SUB>∼24
kpc). We use observations of EC2 to determine its physical
characteristics. A temperature of 20 K was estimated from our ammonia
detections and a gas density of n({H}<SUB>2</SUB>) ∼ 10<SUP>4</SUP>
cm<SUP>-3</SUP> was determined by comparing LVG models of a number
of species to their deconvolved line detections. Taking the clumpy
structure of EC2 into account, we also calculated M<SUB>EC2</SUB>
∼ 10<SUP>4</SUP> M<SUB>sun</SUB>, and from peak continuum emission
we calculated a dust mass for EC2 and a dust-to-gas mass ratio ≥
0.001. To establish the most likely chemical and physical properties
of EC2, we made a pseudo-time-dependent chemical kinetic model. This
uses our observationally derived temperatures and densities, and varies
elemental initial abundances, photon flux, cosmic-ray ionisation rate
and gas-to-dust ratio in an attempt to fit the observed results. We
found that heavy elements may be depleted by a factor of ∼5 relative
to local molecular clouds. The models also suggest a high UV photon
field in EC2 (10-20× local values). Some of our models indicate that
steady-state is reached very quickly after around 5,000 yr. Our observed
high abundances of the radicals C<SUB>2</SUB>H and CN are typical of
photon-dominated regions. This may be related to a large value of the
UV flux to grain surface area compared to local clouds. Our best-fit
models are consistent with reduced elemental abundances and a low
dust-to-gas mass ratio. Such reduced abundances may be attributed to
the low level of star formation in this region, and are probably also
related to the continuing infall of low-metallicity halo gas since
the Milky Way formed. Although EC2 does contain young stars, there is
no evidence of the late-type stars which produce dust grains, thereby
justifying the assumption of a high ratio of UV flux to grain surface
area. We conclude that, despite the position of EC2 in the Galaxy, UV
photons (rather than cosmic rays) play an important role in establishing
its detailed chemical composition. Given that EC2 is in a region of
extremely low gas pressure and very small spiral arm perturbation,
questions remain as to the origin of its morphology and dynamics. A
SNR associated with EC2, GSH 138-01-94, is the largest and oldest SNR
known in the Milky Way. It consists of a H I shell with an expansion
velocity of ∼12 km s<SUP>-1</SUP> and an expansion age of 4.3 Myr,
so EC2 could be as young as the ages derived from our time-dependent
calculations. We conclude that the formation, structure, and subsequent
chemistry of EC2 may be the direct result of shock fronts from GSH
138-01-94 propagating through the medium between 10<SUP>3</SUP> and
10<SUP>4</SUP> yr ago.
---------------------------------------------------------
Title: Innovation in Astronomy Education
Authors: Pasachoff, Jay M.; Ros, Rosa M.; Pasachoff, Naomi
2008iae..book.....P Altcode:
Preface; Part I. General Strategies for Effective Teaching:
Introduction; 1. Main objectives of SpS2; 2. Learning astronomy
by doing astronomy; 3. Hands-on Universe-Europe; 4. Life on Earth
in the atmosphere of the Sun; 5. A model of teaching astronomy to
pre-service teachers; 6. How to teach, learn about, and enjoy astronomy;
7. Clickers: a new teaching tool of exceptional promise; 8. Educational
opportunities in pro-am collaboration; 9. Teaching history of astronomy
to second-year engineering students; 10. Teaching the evolution of
stellar and Milky Way concepts through the ages; 11. Educational efforts
of the International Astronomical Union; 12. Astronomy in culture;
13. Light pollution: a tool for astronomy education; 14. Astronomy by
distance learning; 15. Edible astronomy demonstrations; 16. Amateur
astronomers as public outreach partners; 17. Does the Sun rotate
around Earth or Earth rotate around the Sun?; 18. Using sounds and
sonifications for astronomy outreach; 19. Teaching astronomy and
the crisis in science education; 20. Astronomy for all as part of a
general education; Poster abstracts; Part II. Connecting Astronomy
with the Public: Introduction; 21. A status report from the Division
XII working group; 22. Outreach using media; 23. Astronomy podcasting;
24. IAU's communication strategy, hands-on science communication, and
the communication of the planet definition discussion; 25. Getting a
word in edgeways: the survival of discourse in audiovisual astronomy;
26. Critical evaluation of the new Hall of Astronomy; 27. Revitalizing
astronomy teaching through research on student understanding; Poster
abstracts; Part III. Effective Use of Instruction and Information
Technology: Introduction; 28. ESO's astronomy education program;
29. U.S. student astronomy research and remote observing projects;
30. Global network of autonomous observatories dedicated to student
research; 31. Remote telescopes in education: report of an Australian
study; 32. Visualizing large astronomical data holdings; Poster
abstracts; Part IV. Practical Issues Connected with the Implementation
of the 2003 IAU Resolution: Introduction; 33. Stellar evolution for
students of Moscow University; 34. Astronomy for everybody: An approach
from the CASAO/NAUH view; 35. Toward a new program in astronomy
education in secondary schools in Turkey; 36. Universe awareness
for young children; 37. Education in Egypt and Egyptian responses to
eclipses; 38. Astronomy in the cultural heritage of African societies;
39. Education at the Pierre Auger Observatory: the cinema as a tool in
science education; 40. Freshman seminars: interdisciplinary engagements
in astronomy; 41. Astronomy for teachers; Poster abstracts; Conclusion.
---------------------------------------------------------
Title: Polar Plume Brightening During the 2006 March 29 Total Eclipse
Authors: Pasachoff, J. M.; Rušin, V.; Druckmüller, M.;
Druckmüllerová, H.; Bělík, M.; Saniga, M.; Minarovjech, M.;
Marková, E.; Babcock, B. A.; Souza, S. P.; Levitt, J. S.
2008ApJ...682..638P Altcode:
We discuss a remarkable brightening in a polar plume, as inferred
from unique coordinated observations of the white-light corona
during the total eclipse of the Sun of 2006 March 29. The polar
plume (also known as a polar ray, with distinctions that we discuss)
was observed at the positional angle of 9° the velocity at which
the brightening propagated was about 65 km s<SUP>-1</SUP>, which is
close to the values derived by modeling of mass/energy transfer in
polar plumes/rays as well as to those acquired from images from the
Extreme-ultraviolet Imaging Telescope on the European Space Agency/NASA
Solar and Heliospheric Observatory (SOHO/EIT). Comparing our data with
those from the SOHO/LASCO C2 coronagraph, we estimate the lifetime of
the polar ray to be less than 24 hr.
---------------------------------------------------------
Title: Simultaneous SoHO and TRACE Observations of the Solar
Atmosphere
Authors: Tingle, E. D.; Pasachoff, J. M.
2008AGUSMSP31C..04T Altcode:
From May 24-27, 2004, the Transition Region and Coronal Explorer (TRACE)
and the Solar Ultraviolet Measurement of Emitted Radiation (SUMER)
instrument aboard Solar and Heliospheric Observer (SoHO) simultaneously
observed the northwest and southwest regions of the sun. Through SUMER's
measurements, we made detailed velocity measurements from different
layers of the solar atmosphere corresponding to different temperatures
and emission lines. Original programs written in Interactive Data
Language (IDL) revealed maximum and minimum velocities within the region
populated by spicules from 2,000-10,000 km above the solar limb. These
values were compared to TRACE observations taken in 1600 Å, which
revealed a strong coronal loop feature with a strong blueshifted Si II
(1533.4 Å) emission line and a simultaneously strong redshifted C
IV (1548.2 Å) emission line suggesting differing flows of material
at different temperatures within the loop feature. In this paper, we
seek to further our knowledge of coronal loop evolution and dynamics,
specifically the observed differing temperature flows. We thank Ingolf
Dammasch for his expertise. Obtaining the data was supported in part
by NASA grant NNG04GK44G and the current reduction work is supported in
part by NASA grant NNM07AA01G from NASA's Marshall Space Flight Center.
---------------------------------------------------------
Title: Using SST and TRACE Observations to Test Spicule Models
Authors: Jacobson, W. A.; Pasachoff, J. M.
2008AGUSMSP43B..02J Altcode:
Spicules are jets of plasma that rise out of the solar photosphere at
between 10 and 150 km/s to a maximum height of about 10,000 km. These
jets, which typically live between five and fifteen minutes, make
up the chromosphere and contribute to the heating of the lower solar
atmosphere. Using Interactive Data Language (IDL) for image alignment
and the processing program ImageJ, we were able to determine spicule
statistics from observations taken at the solar limb with the Swedish
1-m Solar Telescope (SST) in July 2006. In addition, Dopplergram movies
allowed for a more complete understanding of spicule formation, motions,
and evolution. This understanding was further enhanced by comparing
simultaneous SST and Transition Region and Coronal Explorer (TRACE)
images, which allowed us to link corresponding spicule-related events
in different layers of the solar atmospheric. We consider our results
in terms of recent spicule models. We thank Mats Lofdahl of the Royal
Swedish Academy of Sciences for his work on Multi-Object Multi-Frame
Blind Deconvolution of the SST data. Obtaining the data was supported
in part by NASA grant NNG04GK44G and the current reduction work is
supported in part by NASA grant NNM07AA01G from NASA's Marshall Space
Flight Center.
---------------------------------------------------------
Title: Chromosphere and Corona for Research and Education
Authors: Pasachoff, Jay M.
2008mear.confE..29P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Hinode's Solar Wonderland
Authors: Pasachoff, Jay M.
2008S&T...115d..64P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Recent Stellar Occultation Observations Using High-Speed,
Portable Camera Systems
Authors: Gulbis, A. A. S.; Elliot, J. L.; Person, M. J.; Babcock,
B. A.; Pasachoff, J. M.; Souza, S. P.; Zuluaga, C. A.
2008AIPC..984...91G Altcode:
We have recently constructed six observing systems identified as POETS
(Portable Occultation Eclipse and Transit System[1]). These systems
are optimized for (i) high-speed, high signal-to-noise observations
at visible wavelengths and (ii) easy transport, to allow mounting
on telescopes worldwide. The Andor iXon cameras have e2v CCD97
(frame transfer) sensors: a 512×512 array of 16-micron pixels, back
illuminated, with peak quantum efficiency >90%. The maximum readout
rate is 32 full frames per second, while binning and subframing can
increase the cadence to a few hundred frames per second. Read noise
in conventional modes goes below 6 electrons per pixel. Further,
an electron-multiplying mode can effectively reduce the read noise
to sub-electron levels, at the expense of dynamic range. The cameras
are operated via a desktop computer that contains a 3 GHz Pentium 4
processor, 2 GB memory, and a 10,000 rpm hard disk. Images are triggered
from a GPS receiver and have an approximately 50 nanosecond timing
uncertainty. Each POETS can be transported as carry-on luggage. Here,
we present instrument details, along with recent results from their
use in stellar occultation observations by small bodies in the outer
solar system. Occultations can produce data of the highest spatial
resolution for any Earth-based observing method; therefore, they play
a key role in determining diameters of distant solar-system bodies
and probing the structure of atmospheres at the microbar level. We
discuss POETS deployments in 2005-2007 to observe stellar occultations
by Charon and Pluto (on 0.6- to 6.5-m telescopes) and future work on
occultations by Kuiper Belt objects.
---------------------------------------------------------
Title: Executive Committee Working Group Young Astronomers Events
Authors: Gerbaldi, Michèle; De Greve, Jean-Pierre; Dovčiak,
Michal; Engvold, Oddbjørn; Guinan, Edward F.; Hearnshaw, John B.;
Johnston-Hollitt, Melanie; Pasachoff, Jay M.; Percy, John R.; Ribas,
Ignasi; White, James C.; Dovčiak, Michal; Goosmann, René; Pecháček,
Tomáš; Stoklasová, Ivana
2007IAUTB..26..242G Altcode:
At the IAU XXV General Assembly in Sydney, 2003, a questionnaire
on the perception of participation of “young astronomers” at IAU
meeting was distributed. Following the conclusions from the analysis of
this questionnaire, the IAU EC recommended in 2004 that the “young
astronomers” concept at the next GA in Prague should be worked out
with specific activities.
---------------------------------------------------------
Title: Commission 46: Astronomy Education and Development
Authors: Pasachoff, Jay M.; Jones, Barrie W.; Hearnshaw, John B.;
Gerbaldi, Michèle; Christensen, Lars Lindberg; Tolbert, Charles R.;
Percy, John R.
2007IAUTB..26..230P Altcode:
The International Astronomical Union (IAU) was founded in 1922 to
“promote and safeguard astronomy . . . and to develop it through
international co-operation”. The IAU is funded through its National
Members. Almost all of the funds supplied from the dues are used for
the development of astronomy.
---------------------------------------------------------
Title: Galactic Edge Clouds. I. Molecular Line Observations and
Chemical Modeling of Edge Cloud 2
Authors: Ruffle, P. M. E.; Millar, T. J.; Roberts, H.; Lubowich,
D. A.; Henkel, C.; Pasachoff, J. M.; Brammer, G.
2007ApJ...671.1766R Altcode: 2007arXiv0708.2740R
Edge Cloud 2 (EC2) is a molecular cloud, about 35 pc in size, with one
of the largest galactocentric distances known to exist in the Milky
Way. We present observations of a peak CO emission region in the cloud
and use these to determine its physical characteristics. We calculate a
gas temperature of 20 K and a density of n(H<SUB>2</SUB>)~10<SUP>4</SUP>
cm<SUP>-3</SUP>. Based on our CO maps, we estimate the mass of EC2
at around 10<SUP>4</SUP> M<SUB>solar</SUB> and continuum observations
suggest a dust-to-gas mass ratio as low as 0.001. Chemical models have
been developed to reproduce the abundances in EC2, and they indicate
that heavy element abundances may be reduced by a factor of 5 relative
to the solar neighborhood (similar to dwarf irregular galaxies and
damped Lyα systems), very low extinction (A<SUB>V</SUB><4 mag) due
to a very low dust-to-gas mass ratio, an enhanced cosmic-ray ionization
rate, and a higher UV field compared to local interstellar values. The
reduced abundances may be attributed to the low level of star formation
in this region and are probably also related to the continuing infall
of primordial (or low-metallicity) halo gas since the Milky Way
formed. Finally, we note that shocks from the old supernova remnant
GSH 138-01-94 may have determined the morphology and dynamics of EC2.
---------------------------------------------------------
Title: Division Xii: Union-Wide Activities
Authors: Trimble, Virginia L.; Andersen, Johannes; Aksnes, Kaare;
Genova, Françoise; Gurshtein, Alexander A.; Johansson, Sveneric;
Pasachoff, Jay M.; Smith, Malcolm G.
2007IAUTB..26..211T Altcode:
Division XII consists of Commissions that formerly were organized under
the Executive Committee, that concern astronomers across a wide range of
scientific sub-disciplines and provide interactions with scientists in a
wider community, including governmental organizations, outside the IAU.
---------------------------------------------------------
Title: Fifty Years Later: My New York City Moonwatch Observations
Authors: Pasachoff, Jay M.
2007AAS...211.2301P Altcode: 2007BAAS...39..774P
When Sputnik was launched on October 4, 1957, I was a member of the New
York City Moonwatch team through the Amateur Astronomers Association. As
14-year-old sophomore at the Bronx High School of Science, I took the
subway, the D train, from the Bronx to the RCA building in Rockefeller
Center, where we observed from the roof. I remember our line or lines
of elbow telescopes and our eventual success in detecting Sputnik
overhead. My talk will include my recent reminiscences as a letter
to the editor of The New York Times; the certificate that the Amateur
Astronomers Association gave to the Pulkovo Observatory in what is now
St. Petersburg, Russia; and a survey of Moonwatch history. I will also
share reminiscences reported from some colleagues.
---------------------------------------------------------
Title: Book review: The Sun Kings: The Unexpected Tragedy of Richard
Carrington and the Tale of How Modern Astronomy Began / Princeton
University Press, Princeton and Oxford, xii + 211 pp., 2007, ISBN
978-0-691-12660-9.
Authors: Pasachoff, Jay M.; Pasachoff, Naomi
2007JHA....38..524P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Electron-Multiplying CCD Imaging: Effectiveness for Stellar
Occultations by Faint Objects
Authors: Gulbis, Amanda A.; Elliot, J. L.; Person, M. J.; Souza,
S. P.; Babcock, B. A.; Pasachoff, J. M.; McKay, A. J.; Zuluaga, C. A.
2007DPS....39.3408G Altcode: 2007BAAS...39..480G
Our Portable Occultation, Eclipse, and Transit Systems (POETS; Souza et
al. 2006, PASP 118, 1550) have been successfully employed for multiple
stellar occultation observations: (i) four systems obtained data in
South America during the 11 July 2005 occultation of C313.2 (2UCAC
26257135) by Charon (Gulbis et al. 2006, Nature 439, 48; Person et
al. 2006, AJ 132 1575); (ii) four systems obtained data in Australia
during the 2006 June 12 occultation of P384.2 (2UCAC 26039859) by Pluto
(Elliot et al. 2007, AJ 134, 1), and (iii) three systems were utilized
in the Southwestern U.S. for the 2007 March 18 occultation of P445.2
(2UCAC 25823784) by Pluto (Person et al. 2007, this meeting). <P />Pluto
and Charon have apparent V magnitudes of 14 and 16, and the stars for
these events had UCAC magnitudes of 14.99 to 15.25. These events were
bright enough to achieve fair to excellent signal-to-noise ratios
(SNRs) at cadences between 2 and 10 Hz by using "conventional”
camera modes. POETS also possess electron-multiplying (EM) readout
modes, which we have not yet employed for occultation observations
because conventional modes have been more than adequate. EM modes have
higher read noise, generate an excess noise factor, and limit dynamic
range; however, signal can be increased by a factor of up to 1000x,
and read noise is effectively eliminated at high EM gain. Here, we
explore the benefits and disadvantages of using EM capability for
observations of stellar occultations by faint bodies. We focus on
prospective occultations by Kuiper Belt objects, predictions of which
are increasingly numerous as fainter stars are considered. We identify
regimes in which EM modes are most effective by analyzing SNR as a
function of exposure time and object/star magnitudes. <P />This work is
supported by NASA Planetary Astronomy grants NNG04GF25G and NNG04GE48G.
---------------------------------------------------------
Title: High Altitude Structure in Pluto's Atmosphere from the 2007
March 18 Stellar Occultation
Authors: Person, Michael J.; Elliot, J. L.; Gulbis, A. A.; Zuluaga,
C. A.; Babcock, B. A.; Pasachoff, J. M.; McKay, A. J.; Souza, S. P.;
Hubbard, W. B.; Kulesa, C. A.; McCarthy, D. W.; Kern, S. D.; Levine,
S. E.; Bosh, A. S.; Ryan, E. V.; Ryan, W. H.; Meyer, A.; Wolf, J.;
Hill, J. M.
2007DPS....39.5214P Altcode: 2007BAAS...39..519P
Visible wavelength observations were made of the 2007 March 18 Pluto
occultation of the star P445.3 (UCAC2 25823784; McDonald and Elliot,
AJ 120, 1599) from five US sites by our consortium (Pasachoff, et al.,
2007, this meeting). Simultaneous model fitting to all of our light
curve data yielded 1207 ± 4 km as the half-light shadow radius of
Pluto's atmosphere. This radius is consistent with the 1208 ± 9 km
result measured in 2006 (Elliot, et al., AJ 134,1) and confirms that
the large increase in atmospheric pressure measured between the 1988
and 2002 (Elliot, et al., Nature 424,165 Sicardy, et al., Nature 424,
168) observations has ceased. Inversion of the highest signal-to-noise
visible light curve, obtained with the Portable Occultation Eclipse
and Transit Systems (POETS; Souza, et al., PASP 118, 1550) at the
6.5-m MMT (MMTO, Fred Lawrence Whipple Observatory, Mt. Hopkins)
resulted in number density, pressure, and temperature profiles for
Pluto's atmosphere in the radius range of 1340 - 1460 km (assuming the
dominant atmospheric component is N<SUB>2</SUB>). These inversions
reveal oscillating deviations of the number density from a simple
exponential profile in Pluto's upper atmosphere that are coherent
across the 1000 km length of the grazing occultation and also in the
300 km line of sight. Here, we interpret this structure as vertically
propagating waves in Pluto's upper atmosphere, and provide a feasible
mechanism for the maintenance of this large-scale coherence in terms
of Rossby planetary waves. This work was partially funded by NASA
Planetary Astronomy grants NNG04GE48G, NNG04GF25G, NNH04ZSS001N, and
NNG05GG75G. Partial funding for MMTO observations was also provided by
Astronomy Camp. Some of the observations reported here were obtained
at the MMT Observatory, a joint facility of the University of Arizona
and the Smithsonian Institution.
---------------------------------------------------------
Title: Observational Results from the 2007 March 18 Pluto Stellar
Occultation
Authors: Pasachoff, Jay M.; Babcock, B. A.; Souza, S. P.; McKay,
A. J.; Person, M. J.; Elliot, J. L.; Gulbis, A. A.; Zuluaga, C. A.;
Hill, J. M.; Ryan, E. V.; Ryan, W. H.
2007DPS....39.6203P Altcode: 2007BAAS...39Q.541P
Our consortium observed the 5-minute occultation by Pluto of the star
we call P445.3 (2UCAC 25823784, UCAC magnitude 15.3; McDonald and
Elliot, 2000, AJ 120, 1599) from sites in the American southwest on
2007 March 17/18 (18 March, UT). Shadow velocity was 6.8 km/s. The
2007 occultation grazed the atmosphere. We were able to use one of
the 8.4-m mirrors of the Large Binocular Telescope Observatory, still
in its engineering stage, though only with its facility guide camera
and not with our Portable Occultation, Eclipse, and Transit System
(POETS) CCD/GPS/computer instruments (Souza et al., 2006, PASP 118,
1550). Because of the accurate GPS timing, we were able to align
the light curve obtained, which included only the second half of
the occultation, with results from other telescopes, including the
visible, beamsplit light curve obtained by our group with the 6.5-m
MMT (Person et al., 2007, this meeting). We also used, with POETS, the
2.4-m Magdalena Ridge Observatory near Socorro, New Mexico; a partial
light curve was obtained despite variable cloudiness throughout the
80 min observation. The location of this telescope was the farthest
into the occultation path, and thus led to the deepest incursion
into Pluto's atmosphere of the starlight of the major telescopes we
used. Light curves were generated by frame-by-frame synthetic-aperture
photometry. The large increase in atmospheric pressure we had earlier
measured at the 2002 occultation compared with measurements at the
first successful Pluto occultation, in 1988, has ceased, as shown by
both the 2006 and the current, 2007 measurements. <P />Acknowledgments:
We thank Richard Green for granting Director's Discretionary time for
the LBT observations. This work was partially funded by NASA Planetary
Astronomy grants NNG05GG75G, NNG04GE48G, NNG04GF25G, and NNH04ZSS001N
to Williams College and to MIT.
---------------------------------------------------------
Title: Special Session 2 Innovation in teaching and learning astronomy
Authors: Ros, Rosa M.; Pasachoff, Jay M.
2007HiA....14..541R Altcode:
On August 17 and 18, 2006, Commission 46 on Astronomy Education and
Development held a Special Session at the IAU XXVI General Assembly
in Prague. The session, on Innovation in Teaching/Learning Astronomy,
was organized around four themes: (i) general strategies for effective
teaching, (ii) connecting astronomy with the public, (iii) effective
use of instruction and information technology, and (iv) practical
issues connected with the implementation of the 2003 IAU Resolution
that recommended including astronomy in school curricula, assisting
schoolteachers in their training and backup, and informing them about
available resources. Approximately 40 papers were presented orally;
in addition, 60 poster papers were displayed.
---------------------------------------------------------
Title: Fine Structures in the White-Light Solar Corona at the
2006 Eclipse
Authors: Pasachoff, J. M.; Rušin, V.; Druckmüller, M.; Saniga, M.
2007ApJ...665..824P Altcode:
Observations of the total solar eclipse of 2006 March 29, as it crossed
Africa from southwest to northeast into a Greek island and beyond,
allowed correlations with near-simultaneous coronal observations
from several spacecraft, including SOHO and TRACE. New methods of
compositing images allow the recovery of higher resolution (1"-2")
on coronal features than had normally been available in the past,
reaching substantially higher resolutions than are currently available
from space. We discuss a variety of the new methods and observations,
and use them to provide the most detailed portrait possible of the Sun,
at least on 2006 March 29.
---------------------------------------------------------
Title: Changes in Pluto's Atmosphere: 1988-2006
Authors: Elliot, J. L.; Person, M. J.; Gulbis, A. A. S.; Souza, S. P.;
Adams, E. R.; Babcock, B. A.; Gangestad, J. W.; Jaskot, A. E.; Kramer,
E. A.; Pasachoff, J. M.; Pike, R. E.; Zuluaga, C. A.; Bosh, A. S.;
Dieters, S. W.; Francis, P. J.; Giles, A. B.; Greenhill, J. G.; Lade,
B.; Lucas, R.; Ramm, D. J.
2007AJ....134....1E Altcode:
The 2006 June 12 occultation of the star P384.2 (2UCAC 26039859)
by Pluto was observed from five sites in southeastern Australia
with high-speed imaging photometers that produced time-series CCD
images. Light curves were constructed from the image time series and
fit by least-squares methods with model light curves. A new modeling
procedure is presented that allows a simultaneous fit of the atmospheric
parameters for Pluto and the astrometric parameters for the occultation
to all of the light curves. Under the assumption of a clear atmosphere
and using this modeling procedure to establish the upper atmosphere
boundary condition, immersion and emersion temperature profiles were
derived by inversion of the Siding Spring light curve, which had
our best signal-to-noise ratio. Above ~1230 km radius, atmospheric
temperatures are ~100 K and decrease slightly with altitude-the same
as observed in 1988 and 2002. Below 1210 km, the temperature abruptly
decreases with altitude (gradients ~2.2 K km<SUP>-1</SUP>), which
would reach the expected N<SUB>2</SUB> surface-ice temperature of
~40 K in the 1158-1184 km radius range. This structure is similar
to that observed in 2002, but a much stronger thermal gradient
(or stronger extinction) is implied by the 1988 light curve (which
shows a “kink” or “knee” at 1210 km). The temperature profiles
derived from inversion of the present data show good agreement with a
physical model for Pluto's atmosphere selected from those presented
by Strobel et al. (1996). Constraints derived from the temperature
profiles (and considering the possibility of a deep troposphere)
yield a value of 1152+/-32 km for Pluto's surface radius. This value
is compared with surface-radius values derived from the series of
mutual occultations and eclipses that occurred in 1985-1989, and the
limitations of both types of measurements for determining Pluto's
surface radius are discussed. The radius of Pluto's atmospheric shadow
at the half-intensity point is 1207.9+/-8.5 km, the same as obtained
in 2002 within measurement error. Values of the shadow radius cast
by Pluto's atmosphere in 1988, 2002, and 2006 favor frost migration
models in which Pluto's surface has low thermal inertia. Those models
imply a substantial atmosphere when New Horizons flies by Pluto in
2015. Comparison of the shape of the stellar occultation light curves
in 1988, 2002, and 2006 suggests that atmospheric extinction, which
was strong in 1988 (15 months before perihelion), has been dissipating.
---------------------------------------------------------
Title: High-spectral-resolution Observations of the Solar Chromosphere
and Corona
Authors: Pasachoff, Jay M.; Bruck, M. A.
2007AAS...210.9507P Altcode: 2007BAAS...39..224P
We continue to reduce high-spectral-resolution observations of the
solar chromosphere from the Swedish 1-m Solar Telescope (SST) and
TRACE; and, at the 29 March 2006 total solar eclipse, of the solar
corona in the [Fe XIV] green line and the [Fe X] red line. (a) The
SST observations in 2006 used the SOUP Lyot filter to observe H-alpha
limb spicules in five positions with 128 milliangstrom resolution for
velocity imaging with several cameras to allow restoration of even
noisy images. One camera is near H-alpha, providing high S/N images for
extracting wavefront information. The other is deliberately defocused
for Phase Diversity information. We use Multi-Object Multi-Frame Blind
Deconvolution (MOMFBD; momfbd.org), assisted by Michiel Van Noort and
Mats Löfdahl (Royal Swedish Academy of Sciences) and the CfA Hinode
center. Simultaneous TRACE observations show spicules in emission and,
silhouetted against the EUV corona, in absorption. (b) Our Fabry-Perot
2006-eclipse coronal spectra were taken with David Rust's (JHUAPL)
0.16 angstrom Y-cut lithium-niobate filter. With Rust and Matthew
Noble, the etalon was stepped across the red coronal line every 0.22
angstrom. We present the profile and Doppler shifts of the [Fe X]
line. (c) We collected simultaneous 10 Hz observations in the red and
green coronal lines at the 2006 eclipse, with the goal of detecting
high-frequency intensity oscillations ( 1 Hz), which can be relevant
to coronal heating, and to confirm previous results. We present FFT
and wavelet analysis of the aligned data. <P />We thank Bryce Babcock
and Steven Souza (Williams) for their eclipse collaboration. We
acknowledge grants NNG04GK44G, NNG04GE48G, and NN05GG75G from NASA
Planetary Astronomy. The eclipse observations were supported by NSF
grant ATM-0552116 from the Solar Terrrestrial Program of the Atmospheres
Sciences Division. Additional eclipse support was received from National
Geographic's Committee on Research and Exploration and Williams's Rob
Spring Fund.
---------------------------------------------------------
Title: (134340) Pluto
Authors: Person, M. J.; Elliot, J. L.; Gulbis, A. A. S.; Zuluaga,
C. A.; Babcock, B. A.; McKay, A. J.; Pasachoff, J. M.; Souza, S. P.;
Hubbard, W. B.; Kulesa, C. A.; McCarthy, D. W.; Kern, S. D.; Levine,
S. E.; Bosh, A. S.; Ryan, E. V.; Ryan, W. H.; Meyer, A.; Wolf, J.
2007IAUC.8825....1P Altcode: 2007IAUC.8825A...1P
M. J. Person, J. L. Elliot, A. A. S. Gulbis, and C. A. Zuluaga,
Massachusetts Institute of Technology; B. A. Babcock, A. J. McKay,
J. M. Pasachoff, and S. P. Souza, Williams College; W. B. Hubbard,
C. A. Kulesa, and D. W. McCarthy, University of Arizona; S. D. Kern,
Space Telescope Science Institute; S. E. Levine, U.S. Naval Observatory;
A. S. Bosh, Boston University; E. V. Ryan and W. H. Ryan, Magdalena
Ridge Observatory; and A. Meyer and J. Wolf, SOFIA, report observations
on Mar. 18 UT of an occultation by (134340) Pluto of the star/event
called P445.3 by McDonald and Elliot (2000, A.J. 120, 1599; see also
http://occult.mit.edu/research/occultations/Pluto/P445.3-preds/). The
occultation was observed from five sites by their consortium (as well
as by others). A preliminary astrometric solution based on the light
curves from all of the stations places Pluto's shadow north of pre-event
predictions. Based on this solution, the closest approach distance of
the center of Pluto's shadow to their successful observation sites are
as follows: Mount Hopkins, 1319 km; Magdalena Ridge, 1192 km; Fremont
Peak, 1019 km; USNO Flagstaff Station, 1102 km; and Mt. Graham, 1258
km. All closest-approach distances are south of Pluto's center in the
shadow plane, perpendicular to the direction to the star and shifted
by the same amount within the uncertainties. The formal error on the
astrometric solution is +/- 4 km, but error bars of +/- 15 km account
for possible systematic effects. The half-light shadow radius from
this solution is 1207 +/- 15 km, consistent with the shadow radius of
1208 +/- 10 km from 2006 (Elliot et al., A.J., in press).
---------------------------------------------------------
Title: Observing solar eclipses in the developing world
Authors: Pasachoff, Jay M.
2007IAUSS...5..265P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Education at the International Astronomical Union Meeting -
Prague Czech Republic
Authors: Ros, Rosa; Pasachoff, Jay
2007Spark...3...14R Altcode:
No abstract at ADS
---------------------------------------------------------
Title: St. Benedict Sees the Light: Asam's Solar Eclipses as Metaphor
Authors: Olson, Roberta J. M.; Pasachoff, Jay M.
2007ReArt..11..299O Altcode:
During the Baroque period, artists worked in a style - encouraged by
the Roman Catholic Church and the Council of Trent - that revealed
the divine in natural forms and made religious experiences more
accessible. Cosmas Damian Asam, painter and architect, and his brother
Egid (Aegid) Quirin Asam, sculptor and stuccatore, were the principal
exponents of eighteenth-century, southern-German religious decoration
and architecture in the grand manner, the Gesamtkunstwerk. Cosmas
Damian's visionary and ecstatic art utilized light, both physical and
illusionistic, together with images of meteorological and astronomical
phenomena, such as solar and lunar eclipses. This paper focuses on his
representations of eclipses and demonstrates how Asam was galvanized
by their visual, as well as metaphorical power and that he studied a
number of them. He subsequently applied his observations in a series
of paintings for the Benedictine order that become increasingly
astronomically accurate and spiritually profound. From the evidence
presented, especially in three depictions of St. Benedict's vision,
the artist harnessed his observations to visualize the literary
description of the miraculous event in the Dialogues of St. Gregory
the Great, traditionally a difficult scene to illustrate, even for
Albrecht Dürer. Asam painted the trio at Einsiedeln, Switzerland
(1724-27); Kladruby, the Czech Republic (1725-27), where he captured
the solar corona and the "diamond-ring effect"; and Weltenburg, Germany
(1735), where he also depicted the diamond-ring effect at a total
solar eclipse. We conclude that his visualizations were informed by his
personal observations of the solar eclipses on 12 May 1706, 22 May 1724,
and 13 May 1733. Asam may have also known the eclipse maps of Edmond
Halley and William Whiston that were issued in advance. Astronomers
did not start studying eclipses scientifically until the nineteenth
century, making Asam's depictions all the more fascinating. So powerful
was the image that Asam invented to visualize St. Benedict's vision
that it found reflection in the subsequent Bavarian Benedictine visual
tradition. Total solar eclipses are among the most spectacular sights
in Nature. Therefore, in an age obsessed with revealing the divine
through natural idioms and making religious experiences direct - not
to mention that light had long functioned as a symbol of divinity in
the Christian tradition - it seems fitting that solar eclipses would
be interpreted as a metaphor of a divine presence or a miracle.
---------------------------------------------------------
Title: POETS: Portable Occultation, Eclipse, and Transit System
Authors: Souza, Steven P.; Babcock, Bryce A.; Pasachoff, Jay M.;
Gulbis, Amanda A. S.; Elliot, J. L.; Person, Michael J.; Gangestad,
Joseph W.
2006PASP..118.1550S Altcode:
Occultations of stars by small bodies in the outer solar system are
opportunities to make high-resolution measurements of their geometries
and orbital elements and to detect or probe their atmospheres. Such
events are limited in space and time, so it is desirable to deploy
highly capable camera systems on multiple fixed and/or portable
telescopes anywhere in the world, potentially on short notice. Similar
considerations apply to planetary transits and solar eclipses. We have
designed a camera system called POETS (Portable Occultation, Eclipse,
and Transit System), which is optimized for occultation and related
observations, and have assembled five such systems. The core of this
system is the Andor Technology DV-887 (now DU-897) frame-transfer
camera, featuring a high frame rate, minimal dead time, high quantum
efficiency, and low read noise. An electron-multiplying mode lowers
effective read noise to below 1 e<SUP>-</SUP> pixel<SUP>-1</SUP>
and is capable of photon counting. Each POETS includes a compact
GPS timing system with microsecond accuracy, and a high-performance
computer system capable of sustained fast frame rates. Each POETS is
designed to be transportable as carry-on luggage and is adaptable to a
wide variety of sites. POETS were deployed for the first time for the
2005 July 11 Charon occultation event, and they performed extremely
well on telescopes with apertures from 0.6 to 6.5 m. Three POETS
were subsequently deployed for the 2006 March 29 total solar eclipse,
and five for the 2006 June 12 Pluto occultation.
---------------------------------------------------------
Title: The April 8, 2005, Eclipse White-Light Corona
Authors: Pasachoff, Jay M.; Kimmel, Shelby B.; Druckmüller, Miloslav;
Rušin, Vojtech; Saniga, Metod
2006SoPh..238..261P Altcode: 2006SoPh..tmp...71P
The hybrid solar eclipse of April 8, 2005, provided a good opportunity
to observe the white-light solar corona, even though the eclipse
lasted just 30 seconds and could be seen only from ships in the Pacific
Ocean. During the eclipse, we detected a unique `cloud' of particles
in the white-light corona above the west limb ≈260°-270°. We
compare this feature with EUV images from SOHO. The feature's density
and temperature seem comparable to a coronal condensation, and, like
a coronal condensation, it is connected to the emergence of material
from the solar surface without a flare. However, the morphology of the
feature shows clear differences from a classical coronal condensation.
---------------------------------------------------------
Title: Charon's Radius and Density from the Combined Data Sets of
the 2005 July 11 Occultation
Authors: Person, M. J.; Elliot, J. L.; Gulbis, A. A. S.; Pasachoff,
J. M.; Babcock, B. A.; Souza, S. P.; Gangestad, J.
2006AJ....132.1575P Altcode: 2006astro.ph..2082P
The 2005 July 11 C313.2 stellar occultation by Charon was observed by
three separate research groups, including our own, at observatories
throughout South America. Here, the published timings from the three
data sets have been combined to more accurately determine the mean
radius of Charon: 606.0+/-1.5 km. Our analysis indicates that a
slight oblateness in the body (0.006+/-0.003) best matches the data,
with a confidence level of 86%. The oblateness has a pole position
angle of 71.4d+/-10.4d and is consistent with Charon's pole position
angle of 67°. Charon's mean radius corresponds to a bulk density of
1.63+/-0.07 g cm<SUP>-3</SUP>, which is significantly less than Pluto's
(1.92+/-0.12 g cm<SUP>-3</SUP>). This density differential favors an
impact formation scenario for the system in which at least one of the
impactors was differentiated. Finally, unexplained differences between
chord timings measured at Cerro Pachón and the rest of the data set
could be indicative of a depression as deep as 7 km on Charon's limb.
---------------------------------------------------------
Title: Pluto's Atmospheric Structure: Results From The 2006 June 12
Stellar Occultation
Authors: Gulbis, Amanda A.; Elliot, J. L.; Person, M. J.; Adams, E. R.;
Kramer, E. A.; Zuluaga, C. A.; Pike, R. E.; Babcock, B. A.; Gangestad,
J. W.; Jaskot, A. E.; Pasachoff, J. M.; Souza, S. P.; Francis, P. J.;
Lucas, R.; Bosh, A. S.; Ramm, D. J.; Greenhill, J. G.; Giles, A. B.;
Dieters, S. W.
2006DPS....38.3101G Altcode: 2006BAAS...38..541G
Observations of the 2006 June 12 occultation by Pluto of P384.2
(McDonald & Elliot, AJ 120, 1599; UCAC2 26039859) were attempted by
the MIT-Williams College collaboration from five sites in Australia and
New Zealand. Four sites were successful: Black Springs, South Australia
(0.8m); Mt. Canopus, Tasmania (1m); Mt. Stromlo, Australian Capital
Territory (1.8m); and Siding Spring, New South Wales (2.3m). Data were
recorded using Portable Occultation, Eclipse, and Transit Systems
(POETS; Souza et al., in preparation). <P />Using these data, we
characterize Pluto's atmosphere and compare our results to previous
occultation observations. Above half-light level, the light curves
exhibit the signature of an isothermal atmosphere. The scale height
is consistent at 60 km, equivalent to a temperature of 110 K for an
N<SUB>2</SUB> atmosphere. Below half-light level, the light curves
resemble those obtained in 2002 (Pasachoff et al., AJ 129, 1718) more
than 1988 (Elliot et al., Icarus 77, 148). The data drop significantly
below the isothermal curve at this level, due either to a thermal
gradient or extinction (or some combination); however, the drop is
not as abrupt as in 1988. Data from 2002 demonstrated that at least
some extinction is at work, due to the wavelength dependence of the
residual flux at the bottom of the light curves (Elliot et al., Nature
424, 165). Unfortunately, we do not have multi-wavelength observations
for P384.2. Our highest signal-to-noise ratio data, from the 2.3m,
exhibit spikes caused by density variations in Pluto's atmosphere
and interesting structure in the bottom of the light curve, when the
star is probing around the limb more than vertically. Data from this
event are also discussed in Elliot et al., a derivation of Pluto's
atmospheric size, and Pasachoff et al., a search for satellites, rings
and debris. <P />Support partially provided by NASA grants NNG04GE48G,
NNG04GF25G, and NNH04ZSS001N.
---------------------------------------------------------
Title: Astronomy through the years
Authors: Pasachoff, Jay M.
2006Natur.443..274P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: A Search for Rings, Moons, or Debris in the Pluto System
during the 2006 July 12 Occultation
Authors: Pasachoff, Jay M.; Babcock, B. A.; Souza, S. P.; Gangestad,
J. W.; Jaskot, A. E.; Elliot, J. L.; Gulbis, A. A.; Person, M. J.;
Kramer, E. A.; Adams, E. R.; Zuluaga, C. A.; Pike, R. E.; Francis,
P. J.; Lucas, R.; Bosh, A. S.; Ramm, D. J.; Greenhill, J. G.; Giles,
A. B.; Dieters, S. W.
2006DPS....38.2502P Altcode: 2006BAAS...38..523P
We examined our data runs from four sites for the 2006 July 12
occultation of the star P384.2 (McDonald & Elliot, AJ 120, 1599,
2000; UCAC2 26039859), to search for moons, rings, or other debris
in the Pluto system. Our data runs extended 80 minutes, or 115,200
km. Motivated by the discovery of P1 (Hydra) and P2 (Nix), each
approximately 50 km in diameter and thought to result from the same
collision that formed Charon, S. A. Stern et al. (Nature 439, 946-948,
2006) suggested that such matter might be detectable. Though their first
estimate was unobservably low at 5×10<SUP>-6</SUP>, it could change
by a factor of 10,000 or more in either direction (Stern, private
communication). Our cloudless data sets, in declining order of S/N,
used our Portable Occultation, Eclipse, and Transit Systems (POETS;
Souza et al., in preparation) and include those from the 2.3-m ANU
telescope at Siding Spring, Australia; 0.8-m Black Springs telescope
near Adelaide, and the 1.8-m EOS telescope at Mt. Stromlo; though
the atmospheric observation time at the 1-m Mt. Canopus Telescope at
Hobart could be recovered from the comparison stars, cloudy intervals
prevent full recovery during the ring/debris possible interval. Our
observing with the 1-m Mt. John University Observatory in New Zealand
was rendered impossible by the lack of electricity resulting from a
major snowstorm. For the ring/debris search, we also evaluated data
from past Pluto (Pasachoff et al., AJ 129, 1718-1723, 2005) and Charon
(Gulbis et al., Nature 439, 48-51, 2006) occultations. See also Elliot
et al. and Gulbis et al. (this meeting). <P />We thank Ian Ritchie of
Electro Optic Systems (Mt. Stromlo Observatory), Ian Bedford, Lyndon
Hemer, and Fraser Farrell (Black Springs Observatory), and Blair Lade
(Stockport Observatory). This work was partially supported by NASA
Planetary Astronomy Grants NNH04ZSS001N, NNG04GE48G, and NNG04GF25G.
---------------------------------------------------------
Title: The Size of Pluto's Atmosphere As Revealed by the 2006 June
12 Occultation
Authors: Elliot, James L.; Person, M. J.; Gulbis, A. A.; Adams,
E. R.; Kramer, E. A.; Zuluaga, C. A.; Pike, R. E.; Pasachoff, J. M.;
Souza, S. P.; Babcock, B. A.; Gangestad, J. W.; Jaskot, A. E.; Francis,
P. J.; Lucas, R.; Bosh, A. S.; Giles, A. B.; Greenhill, J. G.; Dieters,
S. W.; Ramm, D. J.
2006DPS....38.3102E Altcode: 2006BAAS...38..541E
Observations of the 2006 June 12 occultation of P384.2 (McDonald &
Elliot, AJ 120, 1599; aka UCAC2-26039859) were attempted at five sites
by the MIT-Williams occultation group. Four were successful: the 0.8-m
telescope at the Star Castle Observatory in Black Springs, the 1 m
at the Mt. Canopus Observatory in Hobart, the 1.8 m at Mt. Stromlo,
and the 2.3-m ANU telescope at Siding Spring. The data were recorded
with our Portable Occultation, Eclipse, and Transit Systems (POETS;
Souza et al., in preparation). These telescopes were located on both
sides of the centerline and yielded light curves of good to excellent
signal-to-noise ratio, in spite of Pluto being located 15º deg from
a 15.7 day-old-moon. Above the 0.50 stellar flux level (and somewhat
below it), Pluto's atmosphere is well described by an isothermal
model, having the same scale height (within the errors) at all of our
stations. Thus the 0.50 flux level provides a well-defined, consistent
fiducial for measuring the radius of Pluto's atmosphere. All eight
occultation timings (immersion and emersion at each station) were used
in a least-squares fit for the radius. Results will be compared with
Pluto's atmospheric size in 2002 (Person et al., Icarus, submitted),
which had expanded significantly from that reported in 1988 (Elliot
et al., Nature 424, 165). Pluto's atmospheric structure as derived
from these data is discussed in the abstract by Gulbis et al. and
the use of these data to probe for unknown satellites and debris in
the Pluto-Charon system is discussed in the abstract by Pasachoff
et al. This work was partially supported by NASA Planetary Astronomy
Grants NNG04GE48G, NNG04GF25G, and NNH04ZSS001N.
---------------------------------------------------------
Title: Main Objectives for this I.A.U. Special Session on Innovation
in Teaching/ Learning Astronomy
Authors: Pasachoff, J. M.; Ros, R. M.
2006IAUSS...2E...1P Altcode:
In the IAU resolution on the Value of Astronomy Education, passed by the
IAU's General Assembly in 2003, it was recommended: to include astronomy
in school curricula, to assist schoolteachers in their training and
backup, and to inform teachers about available resources. The aim of
this Special Session 2 on "Innovation in Teaching/Learning Astronomy"
is to contribute to the implementation of these recommendations,
introducing innovative points of view regarding methods of
teaching and learning. Astronomers from all countries—developed or
developing—will be equally interested. New methods of dissemination
of information are making big changes in the opportunity of spreading
astronomical knowledge. The World Wide Web continues to expand its
reach, and the Astronomy Picture of the Day reaches the homepage of
millions. The new phenomenon of podcasts is spreading rapidly. Astronomy
attracts many young people to education in important fields in science
and technology. But in many countries, astronomy is not part of the
standard curriculum, and teachers do not receive adequate education
and support. Still, many scientific and educational societies and
government agencies have produced materials and educational resources
in astronomy for all educational levels. Technology is used in
astronomy both for obtaining observations and for teaching. In any
case, it is useful to take their special opportunity to learn about
the situation in different countries, to exchange opinions, and to
collect information in order to continue, over at least the next
triennium, the activities related to promoting astronomy throughout
the world. In particular, we would like to invite all participants to
explain their positive original experiences so they can be adapted for
other regions. Everyone is invited to exchange their initiatives and
to try to involve other countries in common projects. All of us are
in the same boat. http://www.communicatingastronomy.org/innovation2006/
---------------------------------------------------------
Title: Fabry-Perot Interferometric Study of the Green Coronal line
during the Total Eclipse of 2001 from Zambia
Authors: Chandrasekhar, T.; Ashok, N. M.; Rao, B. G. A.; Pasachoff,
J. M.; Suer, Terry-Ann
2006IAUJD...3E...2C Altcode:
We report an interesting ground based Fabry-Perot interferometric
experiment on the green coronal line at 5303 Å carried out successfully
during the total eclipse of 21 June 2001 from Lusaka.Unlike as in
earlier experiments a cooled CCD was used to record as many as 17
Interferograms during the 194 sec of totality. The instrumental profile
is well determined by a green He-Ne laser and has a FWHM of 0.2 Å. The
Fabry-Perot was off centred with respect to the solar disk to permit
wider fringe coverage of the corona. Radial scans from fringe centre
of only one interferogram number over 500 and each scan has several
fringes. The data base spread over 17 interferograms is huge and has
been only partially analysed. Line width temperatures derived from
fringes analysed so far range from 2.4 to 3.7 million degrees and
many profiles are asymmetric. The data base permits a search of line
width oscillations at many positions in the corona with a temporal
resolution of a few seconds which has implications for wave heating
of the corona. Details of the experiment and emerging results will
be presented.
---------------------------------------------------------
Title: Cosmic Deuterium and Social Networking Software
Authors: Pasachoff, J. M.; Suer, T. -A.; Lubowich, D. A.; Glaisyer, T.
2006IAUSS...2E..79P Altcode:
For the education of newcomers to a scientific field and for the
convenience of students and workers in the field, it is helpful to have
all the basic scientific papers gathered. For the study of deuterium
in the Universe, in 2004-5 we set up http://www.cosmicdeuterium.info
with clickable links to all the historic and basic papers in the field
and to many of the current papers. Cosmic deuterium is especially
important because all deuterium in the Universe was formed in the
epoch of nucleosynthesis in the first 1000 seconds after the Big Bang,
so study of its relative abundance (D:H~1:100,000) gives us information
about those first minutes of the Universe's life. Thus the understanding
of cosmic deuterium is one of the pillars of modern cosmology, joining
the cosmic expansion, the 3 degree cosmic background radiation,
and the ripples in that background radiation. Studies of deuterium
are also important for understanding Galactic chemical evolution,
astrochemistry, interstellar processes, and planetary formation. Some
papers had to be scanned while others are available at the Astrophysical
Data System, adswww.harvard.edu, or to publishers' Websites. By 2006,
social networking software (http:tinyurl.com/ zx5hk) had advanced with
popular sites like facebook.com and MySpace.com; the Astrophysical
Data System had even set up MyADS. Social tagging software sites like
http://del.icio.us have made it easy to share sets of links to papers
already available online. We have set up http://del.icio.us/deuterium to
provide links to many of the papers on cosmicdeuterium.info, furthering
previous del.icio.us work on /eclipses and /plutocharon. It is easy
for the site owner to add links to a del.icio.us site; it takes merely
clicking on a button on the browser screen once the site is opened and
the desired link is viewed in a browser. Categorizing different topics
by keywords allows subsets to be easily displayed. The opportunity
to expose knowledge and build an ecosystem of web pages that use the
functionality of a facebook-type application to capture knowledge
collaboratively is considerable. Setting up such a system would marry
one of the youngest isotopes with the latest software technologies.
---------------------------------------------------------
Title: Observing Solar Eclipses in the Developing World
Authors: Pasachoff, J. M.
2006IAUSS...5E..29P Altcode:
The paths of totality of total solar eclipses cross the world, with
each spot receiving such a view about every 300 years. The areas of the
world from which partial eclipses are visible are much wider. For the
few days prior to a total eclipse, the attention of a given country
is often drawn toward the eclipse, providing a teachable moment that
we can use to bring astronomy to the public's attention. Also, it is
important to describe how to observe the partial phases of the eclipse
safely. Further, it is important to describe to those people in the
zone of totality that it is not only safe but also interesting to view
totality. Those who are misled by false warnings that overstate the
hazards of viewing the eclipse, or that fail to distinguish between
safe and unsafe times for naked-eye viewing, may well be skeptical when
other health warnings--perhaps about AIDS or malaria prevention or polio
inoculations--come from the authorities, meaning that the penalties
for misunderstanding the astronomical event can be severe. Through the
International Astronomical Union's Working Group on Solar Eclipses and
through the I.A.U.'s Program Group on Public Education at the Times
of Eclipses, part of the Commission on Education and Development,
we make available information to national authorities, to colleagues
in the relevant countries, and to others, through our Websites at
http://www.eclipses.info and http://www.totalsolareclipse.net and
through personal communication. Among our successes at the 29 March
2006 total solar eclipse was the distribution through a colleague in
Nigeria of 400,000 eye-protection filters.
---------------------------------------------------------
Title: Education Efforts of the International Astronomical Union
Authors: Pasachoff, J. M.
2006IAUSS...2E...6P Altcode:
I describe the education activities of the International Astronomical
Union, particularly the work of Commission 46 on Education and
Development. We are most interested in education in schools and
for general university education rather than for pre-professional
training or graduate schools. We have over 75 National Liaisons,
mostly from member countries of the I.A.U. but some from nonmembers
or regional groupings. We operate through 10 program groups, which are
described at our Website at http://www.astronomyeducation.org. We also
organize Special Sessions at General Assemblies of the International
Astronomical Union, such as this Special Session 2 on Innovation
in Teaching/ Learning Astronomy Methods, organized by Rosa Ros and
me, and Special Session 5 on Astronomy for the Developing World,
organized by John Hearnshaw. A modified version of our Special Session
from the 2003 Sydney General Assembly was published as Teaching and
Learning Astronomy: Effective Strategies for Educators Worldwide (Jay
M. Pasachoff and John R. Percy, eds., Cambridge University Press,
2005). Michele Gerbaldi and Ed Guinan run the International Schools
for Young Astronomers. Jay White heads the Teaching Astronomy for
Development Program Group. John Hearnshaw runs the Program Group
for the Worldwide Development of Astronomy. Charles Tolbert and John
Percy run an Exchange of Astronomers program with a limited number of
grants for stays of over three months between astronomers in developing
countries and established astronomical institutions. Barrie Jones, as
vice-president, aided by Tracey Moore, runs the Newsletter and keeps
track of the National Liaisons list. I run the Program group of Public
Education at the Times of Solar Eclipses.
---------------------------------------------------------
Title: In Retrospect: Out of the darkness
Authors: Pasachoff, Jay M.
2006Natur.442..986P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Narrow-band Filter Observations of the Red-Line Corona at
the 29 March 2006 Eclipse
Authors: Rust, David M.; Noble, M. W.; Pasachoff, J. M.; Babcock,
B. A.; Bruck, M. A.; Wittenmyer, R. A.
2006SPD....37.0110R Altcode: 2006BAAS...38..217R
We report on observations of the corona above active region NOAA 10866,
which was on the solar east limb at S 06 on 29 March 2006. Filtergrams
were obtained at six 0.22 Å steps across the profile of the Fe
X line at 6374.5 Å during the total solar eclipse, starting at
about 1052 UT. The telescope was a 35-cm Schmidt-Cassegrain Meade
RCX400 with the solar image relayed to a 512 x 512-pixel Andor Ixon
DV887 CCD camera via telecentric optics and two narrow-bandpass
filters: (1) a 2 Å thin-film Andover Corp. blocker and (2) a 0.16
Å tunable Fabry-Perot etalon, made by the CSIRO Australian Centre
for Precision Optics. The F-P etalon is a Y-cut lithium niobate wafer
of 0.200-mm thickness coated with reflective and conductive thin-film
layers. Application of a voltage to the etalon produces a passband shift
of 0.0011 Å/volt. Calibration at the eclipse site in Kastellorizo,
Greece, was maintained by reference to a WSTech thermo-electrically
stabilized diode laser tuned to 6375.16 Å. The profile and Doppler
shifts of the Fe X line will be discussed.The expedition was supported
by NSF (ATM-0552116), the Committee for Research and Exploration of
the National Geographic Society, NASA's Planetary Astronomy Division
for the CCD cameras (NNG04GE48G), Sigma Xi, and the Rob Spring Fund
and the Ryan Patrick Gaishin Fund at Williams College.
---------------------------------------------------------
Title: High-Resolution Observations of Limb Spicules from the
Transition Region and Coronal Explorer and the Swedish Solar Telescope
Authors: Westbrook, Owen; Pasachoff, J. M.; Kozarev, K. A.; Yee, J.
2006SPD....37.0202W Altcode: 2006BAAS...38..221W
We observed spicules at the solar limb with TRACE and the Swedish Solar
Telescope on La Palma for four-day intervals in 2004 and 2005 as well
as simultaneous SUMER/SOHO observations in 2004. We are evaluating
the apparent motion of individual spicules to infer chromospheric
heat flow and mass transfer and to improve the statistics of basic
spicule parameters including height, velocity, and inclination. We
use the highest available cadence to measure height vs. time curves,
using parabolic and linear fits to extract average maximum heights and
apparent velocities of rise and descent. Our semiautomatic measurements
of several dozen individual Ca II H spicules find an average height
of 7610 ± 20 km based on ballistic fits and 7990 ± 80 km based on
linear fits, with average velocities 8.7 ± 0.2 km/s ascending and 5.6
± 0.1 km/s descending. Our TRACE data include observations at 1600 Å,
171 Å, and Lyman-alpha; our SST observations using Lockheed Martin's
SOUP include H-alpha (four wing wavelengths to measure velocities)
and Ca II H. We are investigating the relationships between spicule
height and intensity to search for evidence of sheathed vs. monolithic
spicule models, and analyzing ionization fadeout vs. velocity
reversals for limiting spicule heights. A third yearly session of
simultaneous TRACE/SST observations is scheduled.We thank S. P. Souza,
B. De Pontieu, L. Golub, and J. Cirtain; earlier collaboration by
D. B. Seaton, J. P. Shoer, D. L. Butts, and J. W. Gangestad; as well
as the Royal Swedish Academy of Sciences. Support was provided by a
NASA/Solar-Terrestrial Guest Investigator Grant for TRACE (NNG04GK44G),
from Sigma Xi, and from the NASA/Massachusetts Space Grant.
---------------------------------------------------------
Title: Deuterium in the Galactic Center: Evidence for a Cosmological
Origin of D and the Infall of D Enriched Gas
Authors: Lubowich, D. A.; Pasachoff, J. M.; Roberts, H. R.; Millar,
T. J.; Henkel, C.; Brammer, G.
2006AAS...20721703L Altcode:
If deuterium is produced via any stellar or Galactic nucleosynthesis
process, then its abundance would be a maximum value in the Galactic
Center (GC). Conversely, if there are no additional Galactic source
of D, then astration would reduce the initial D abundance in the
GC by 10<SUP>7</SUP> to D/H = (2-4)×10<SUP>-12</SUP>. We used the
Arizona Radio Observatory and detected the J = 1-0 lines of DCN and
H<SUP>15</SUP>CN in four GC molecular clouds located from 10-100 pc
from the GC (Sgr A 50 km s<SUP>-1</SUP>; Sgr A 20 km s<SUP>-1</SUP>;
Sgr B2; and G0.13-0.13 in the magnetic arc). We did not detect DCN or
H<SUP>15</SUP>CN in the circumnuclear disk located 2 pc from the GC
where any D is probably destroyed by a faster rate of astration. We
used a 5300 chemical reaction model to analyze DCN (used to trace
D) and D fractionation, which always enhances the abundance of D
molecules. We estimate the underlying D/H ratio in the GC to be D/H
= (2-5)×10<SUP>-6</SUP> which is in agreement with the results of
Lubowich et al. (2000, Nature, 405, 1025; D/H = 1.7×10<SUP>-6</SUP>)
from DCN observations in one GC cloud. The GC D/H ratios are less than
the local ISM D/H ratio but 10<SUP>6</SUP> times larger than D/H ratios
predicted by chemical evolution models without an additional source
of D. The most likely source of this additional D is the continuous
infall of low-metallicty gas enhanced with D which would negate much
of the effects of astration. Thus, there are no significant Galactic
sources of deuterium, D is primarily cosmological, and the Galaxy
has not had quasar or AGN activity in the past 1 Gyr. <P />DAL was
supported by an AAS Small Research Grant
---------------------------------------------------------
Title: Coronal Observations at the 29 March 2006 Total Solar Eclipse
Authors: Pasachoff, J. M.; Babcock, B. A.; Souza, S. P.; Bruck, M. A.;
Hess, P. W.; Kimmel, S. B.; Levitt, J. S.; Steele, A. S.; Tsykalova,
A. E.; Rust, D. M.; Noble, M. W.; Wittenmyer, R.; Kern, J.; Hawkins,
R. L.; Seiradakis, J. H.; Voulgaris, A.; Pistikoudis, G.; Nestoras,
J.; Demianski, M.
2006SPD....37.0107P Altcode: 2006BAAS...38Q.216P
We report on our eclipse expedition to Kastellorizo, Greece, in the
Dodecanese off the Turkish coast. We observed 3 min 00 sec of totality
on 29 March 2006. All our observations worked very well. One of them
was high-time-resolution (10 Hz) observations in the coronal green
line looking at coronal loops; another was similar observations in
the coronal red line; both are to determine among theories of coronal
heating and continue earlier reports of excess Fourier power in the 1
Hz range. As we knew from SOHO observations from the day before the
eclipse, an active region was stationed right on the east limb and
it gave us very suitable loops to study, with pointing in agreement
with TRACE. A third set of observations used a very narrow-band filter
(Fabry-Perot), with 1/6 angstrom resolution, to make velocity (Doppler)
images of the same coronal loops. A fourth set of observations used a
telescope we had built to match the size of the now defunct innermost
coronagraph on the NASA/ESA SOHO, and it indeed was used to merge with
SOHO EIT disk coronal images and SOHO LASCO outer coronal coronagraph
images. Further, radial-filter "Newkirk camera" images captured
the role of magnetic fields in shaping coronal streamers, which we
also display in mergers of images with sequential exposure times. <P
/>The expedition was supported by NSF (ATM-0552116), the Committee
for Research and Exploration of the National Geographic Society,
NASA's Planetary Astronomy Division for the CCD cameras (NNG04GE48G),
Sigma Xi, and the Rob Spring Fund and the Ryan Patrick Gaishin Fund
at Williams College.
---------------------------------------------------------
Title: The Effect of the Transit of Venus on ACRIM's Total Solar
Irradiance Measurements: Implications for Transit Studies of
Extrasolar Planets
Authors: Schneider, G.; Pasachoff, J. M.; Willson, Richard C.
2006ApJ...641..565S Altcode: 2005astro.ph.12251S
We have used the 2004 June 8 transit of Venus (ToV) as a surrogate
to test observing methods, strategies, and techniques that are being
contemplated for future space missions to detect and characterize
extrasolar terrestrial planets (ETPs) as they transit their host
stars, notably NASA's Kepler mission, planned for 2008. As an analog
to “Kepler-like” photometric transit observations, we obtained
(spatially unresolved) radiometric observations with the ACRIM 3
instrument on ACRIMSAT at a sampling cadence of 131 s to follow the
effect of the ToV on the total solar irradiance (TSI). Contemporaneous
high-resolution broadband imagery with NASA's TRACE spacecraft
provided, directly, measures of the stellar (solar) astrophysical
noise that can intrinsically limit such transit observations. During
the Venus transit, which lasted ~5.5 hr, the planet's angular diameter
was approximately 1/32 the solar diameter, thus covering ~0.1% of the
stellar surface. With our ACRIM 3 data, we measure temporal changes in
TSI with a 1 σ per sample (unbinned) uncertainty of approximately 100
mW m<SUP>-2</SUP> (0.007%). A diminution in TSI of ~1.4 W m<SUP>-2</SUP>
(~0.1%, closely corresponding to the geometrically occulted area of
the photosphere) was measured at mid-transit compared with a mean
pre-/post-transit TSI of ~1365.9 W m<SUP>-2</SUP>. The radiometric
light curve is complex because of the parallactic motion of Venus
induced by ACRIMSAT's near-polar orbit, but exhibits the characteristic
signature of photospheric limb darkening. These observations serve
as a surrogate for future photometric observations of ETPs, such as
Kepler will deliver. Detailed analysis of the ToV, a rare event within
our own solar system, with time-resolved radiometry augmented with
high-resolution imagery, provides a useful analog for investigating
the detectability and characterization of ETPs from observations that
are anticipated in the near future.
---------------------------------------------------------
Title: Film: Big trip to the red planet
Authors: Pasachoff, Jay
2006Natur.440...28P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Charon's radius and atmospheric constraints from observations
of a stellar occultation
Authors: Gulbis, A. A. S.; Elliot, J. L.; Person, M. J.; Adams, E. R.;
Babcock, B. A.; Emilio, M.; Gangestad, J. W.; Kern, S. D.; Kramer,
E. A.; Osip, D. J.; Pasachoff, J. M.; Souza, S. P.; Tuvikene, T.
2006Natur.439...48G Altcode:
The physical characteristics of Pluto and its moon, Charon, provide
insight into the evolution of the outer Solar System. Although previous
measurements have constrained the masses of these bodies, their radii
and densities have remained uncertain. The observation of a stellar
occultation by Charon in 1980 established a lower limit on its radius
of 600km (ref. 3) (later refined to 601.5km ref. 4) and suggested
a possible atmosphere. Subsequent, mutual event modelling yielded a
range of 600-650km (ref. 5), corresponding to a density of 1.56 +/-
0.22gcm<SUP>-3</SUP> (refs 2, 5). Here we report multiple-station
observations of a stellar occultation by Charon. From these data,
we find a mean radius of 606 +/- 8km, a bulk density of 1.72 +/-
0.15gcm<SUP>-3</SUP>, and rock-mass fraction 0.63 +/- 0.05. We do
not detect a significant atmosphere and place 3σ upper limits on
atmospheric number densities for candidate gases. These results seem
to be consistent with collisional formation for the Pluto-Charon
system in which the precursor objects may have been differentiated,
and they leave open the possibility of atmospheric retention by the
largest objects in the outer Solar System.
---------------------------------------------------------
Title: Book Review - Theaters of Time and Space: American Planetaria,
1930-1970
Authors: Pasachoff, Jay M.
2006AEdRv...4b.106P Altcode: 2005AEdRv...4b.106.
No abstract at ADS
---------------------------------------------------------
Title: Book Review: THEATERS OF TIME AND SPACE: AMERICAN PLANETARIA,
1930- 1970 / Rutgers University Press, 2005
Authors: Pasachoff, Jay M.
2006AEdRv...4b..12P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book Review: THE SUN / Abrams, 2006
Authors: Pasachoff, Jay M.
2006SB&F...42..257P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Charon's Radius and Atmospheric Constraints from the 2005
July 11 Stellar Occultation
Authors: Gulbis, A. A. S.; Elliot, J. L.; Person, M. J.; Adams,
E. R.; Kern, S. D.; Kramer, E. A.; Babcock, B. A.; Gangestad, J. W.;
Pasachoff, J. M.; Souza, S. P.; Osip, D. J.; Emililo, M.; Tuvikene, T.
2005DPS....37.5505G Altcode: 2005BAAS...37.1571G
On 2005 July 11 (UT), Charon occulted the star “C313.2" (originally
identified as a Pluto occultation star [McDonald & Elliot,
Astron. J. 120, 1599, 2000]; UCAC2 26257135; R = 14.8). We arranged
to observe this event using five telescopes at four sites: the 0.6-m
at Pico dos Dias Obs. (Brazil), the 0.84-m at Obs. Cerro Armazones,
the 2.5-m du Pont and 6.5-m Clay at Las Campanas Obs., and the 8-m
Gemini South at Cerro Pacha (Chile). The observations were successful
at all stations excluding Pico dos Dias, which was clouded out. <P
/>The Acquisition Camera was employed at Gemini South, while the
remaining sites used POETS (Portable Occultation, Eclipse, and
Transit Systems). Each system utilized a high-speed camera, a control
computer, and a GPS to establish accurate timing. The cameras contain
back-illuminated CCDs, with > 90% quantum efficiency, ∼ 6 electrons
read noise, and 1.74 ms deadtime during frame transfer. For this event,
data rates were 2 - 10 Hz and signal-to-noise ratios were 28 - 273
(normalized to 1 s). The Clay telescope light curve had high enough
time resolution and signal-to-noise to detect the first diffraction
fringe. <P />This dataset marks significant improvement over the only
previously viewed stellar occultation by Charon (Walker, MNRAS 192, 47,
1980; Elliot & Young, Icarus 89, 244, 1991). By fitting the light
curves with models derived from French and Gierasch (Astron. J. 81, 445,
1976), we have calculated Charon's radius and placed strong constraints
on an atmosphere. These results seem consistent with a collisional
origin of the Pluto-Charon system in which either of the precursor
bodies may have been differentiated (McKinnon, Astrophys. J. Lett. 344,
L41, 1989). <P />Support provided, in part, by NASA Planetary Astronomy
grants NNG04GE48G, NNG04GF25G, and NNH04ZSS001N, IAP P5/36 of the
Belgian Federal Office, and BIL 01/3 of the Flemish Ministry.
---------------------------------------------------------
Title: Teaching and Learning Astronomy
Authors: Pasachoff, Jay; Percy, John
2005tla..book.....P Altcode:
Preface; Part I. Astronomy in the Curriculum Around the World:
Preface; 1. Why astronomy is useful and should be included in
the school curriculum John R. Percy; 2. Astronomy and mathematics
education Rosa M. Ros; 3. Astronomy in the curriculum around the
world; 4. Engaging gifted science students through astronomy Robert
Hollow; 5. Poster highlights: astronomy in the curriculum around the
world; Part II. Astronomy Education Research: Preface; 6. Astronomy
education research down under John M. Broadfoot and Ian S. Ginns;
7. A contemporary review of K-16 astronomy education research Janelle
M. Bailey and Timothy F. Slater; 8. Implementing astronomy education
research Leonarda Fucili; 9. The Astronomy Education Review: report on a
new journal Sidney C. Wolff and Andrew Fraknoi; 10. Poster highlights:
astronomy education research; Part III. Educating Students: Preface;
11. Textbooks for K-12 astronomy Jay M. Pasachoff; 12. Distance/internet
astronomy education David H. McKinnon; 13. Educating students with
robotic telescopes - open discussion; 14. Poster highlights - educating
students; Part IV. Educating teachers: Preface; 15. Pre-service
astronomy education of teachers Mary Kay Hemenway; 16. In-service
education of teachers Michèle Gerbaldi; 17. Poster highlights:
educating teachers; Part V. Astronomy and Pseudoscience: Preface;
18. Astronomy, pseudoscience and rational thinking Jayant V. Narlikar;
19. Astronomical pseudosciences in North America John R. Percy and Jay
M. Pasachoff; Part VI. Astronomy and Culture: Preface; 20. Teaching
astronomy in other cultures: archeoastronomy Julieta Fierro; 21. Poster
highlights: astronomy and culture; Part VII. Astronomy in Developing
Countries: Preface; 22. Astronomy Curriculum for developing countries
Case Rijsdijk; 23. Science education resources for the developing
countries James C. White II; Part VIII. Public Outreach in Astronomy:
Preface; 24. What makes informal education programs successful? Nahide
Craig and Isabel Hawkins; 25. The role of science centers and
planetariums Nick Lomb; 26. Science education for the new century -
a European perspective Claus Madsen; 27. Communicating astronomy to
the public Charles Blue; 28. Poster highlights: public outreach in
astronomy; Part IX. The Education Programs of the IAU: Preface; 29. A
short overview of astronomical education carried out by the IAU Syuzo
Isobe; Part X. Discussion; Index.
---------------------------------------------------------
Title: Astronomy education research
Authors: Pasachoff, Jay M.
2005AmJPh..73..997P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book Review—Theaters of Time and Space: American Planetaria,
1930-1970 by Jordan D. Marché
Authors: Pasachoff, Jay M.
2005AEdRv...4..106P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Chandra Observations of Open Cluster h Per
Authors: Evans, N. R.; Wolk, S.; Bizunok, N.; Spitzbart, B.; Seward,
F.; Kenyon, S.; Barnes, T.; Pasachoff, J. M.
2005JRASC..99R.136E Altcode:
We have obtained a 40 ksec ACIS observation of the open star cluster
h Per in December 2004, from which we have identified more than 200
X-ray sources and found optical counterparts for many of them. We are
processing the h Per data with the ANCHORS pipeline, which is being used
to process Chandra observations of star forming regions in a uniform
manner. This will provide fits to the instrumental low-resolution
spectra for cool pre-main sequence stars in h Per including fluxes,
temperatures, and absorption.
---------------------------------------------------------
Title: Chandra observations of open cluster h Per.
Authors: Evans, N. R.; Wolk, S.; Bizunok, N.; Spitzbart, B.; Seward,
F.; Kenyon, S.; Barnes, T.; Pasachoff, J. M.
2005JRASC..99..136E Altcode: 2005JRASC..99V.136E
We have obtained a 40 ksec ACIS observation of the open star cluster
h Per in December, 2004, from which we have identified more than 200
X-ray sources and found optical counterparts for many of them. We are
processing the h Per data with the ANCHORS pipeline which is being used
to process Chandra observations of star forming regions in a uniform
manner. This will provide fits to the instrumental low resolution
spectra for cool pre-main sequence stars in h Per including fluxes,
temperatures and absorption.
---------------------------------------------------------
Title: Portable, Photon-Counting Cameras for Observing Occultations,
Eclipses, and Transits
Authors: Gulbis, A. A. S.; Elliot, J. L.; Person, M. J.; Babcock,
B. A.; Pasachoff, J. M.; Souza, S. P.
2005DPS....37.1810G Altcode: 2005BAAS...37T.651G
Occultations, eclipses, and transits can produce data of the highest
spatial resolution for any Earth-based observing method and are
thus used to determine planetary diameters and probe atmospheric
profiles. Observing these events requires precise geographic and
temporal information. For occultations, the size of the shadow on the
Earth is a function of the occulting body's size and distance. This
shadow is significantly smaller than the Earth's angular diameter
for objects in which we are particularly interested (Triton, Pluto,
Charon, and Kuiper belt objects). Therefore, instruments capable of
traveling to a predicted shadow path increase the opportunities for
observing events. Having multiple systems is also beneficial, since
multiple chords must be observed to derive a body's shape. <P />We
have constructed four portable observing systems (POETS; Portable
Occultation Eclipse and Transit Systems), which can be transported
as carry-on luggage and attached to portable or fixed telescopes. The
cameras have E2V CCD97 sensors: a 512 x 512 array of 16 micron pixels,
back illuminated, with > 90% QE. The CCDs are thermoelectrically
cooled to ∼80 degrees C in air. Readout modes are 1, 3, 5 and 10 MHz,
with a maximum data rate of 32 full frames per second. Binning and
subframes increase the rate to a few hundred frames per second. The
lowest achievable read noise in conventional mode is approximately
6 electrons. One of the two amplifiers employs electron multiplying
gain, which effectively reduces the read noise to sub-electron levels
and allows the cameras to be used for counting photons. Event timing is
done using a state-of-the-art GPS receiver to trigger images. We present
details of the systems, an analysis of the use of photon counting in
the field of small body occultations, and sample occultation data. <P
/>Funding for this work is provided by NASA Planetary Astronomy grants
NNG04GE48G, NNG04GF25G, and NNH04ZSS001N.
---------------------------------------------------------
Title: Deuterium Nucleosynthesis in AGN: Is D Cosmological?
Authors: Lubowich, D. A.; Kuno, N.; Roberts, H.; Millar, T. J.;
Henkel, C.; Pasachoff, J.; Mauersberger, R.
2005NuPhA.758..795L Altcode:
Although deuterium is predicted to be primarily cosmological, D
can also be produced by cosmic-ray or γ-ray spallation reactions -
possibly between high energy jets and the surrounding gas in AGN. We
used the Nobeyama mm array with a 3" resolution (200 pc) in April 2003
to search for any enhanced D from the DCN J = 2 1 line in the 45"×45"
(3 kpc) circumnuclear region of the Seyfert galaxy NGC 1068. NGC
1068 is an optimal target because it has jets, starburst activity, a
circumuclear molecular ring and molecular disk, dense optically thick
concentrations of HCN, and a low-energy X-ray flux of 10<SUP>42</SUP>
erg/s (the highest X-ray flux of any galaxy in which HCN has been
detected and the flux required to produce high D abundances). Although
DCN is detected in most Galactic or LMC molecular clouds with optically
thick HCN, we did not detect DCN with S<SUB>rms</SUB> = 11 mJy/beam
or T<SUB>rms</SUB> = 35.6 mK. Thus our 3σ upper limits are S⩽ 33
mJy/beam or T<SUB>mb</SUB> ⩽ 106.7 mK and DCN/HCN⩽ 0.0044. Using
our 5260 reaction chemical network we estimate the underlying D/H⩽
1.5×10<SUP>-5</SUP> less than or equal to but not greater than the
local Galactic ISM D/H = 1.5 × 10<SUP>-5</SUP>. Thus there is no
significant D production in the nuclear region of NGC 1068 and NGC
1068 has probably not had a recent period of activity with a γ-ray
or cosmic-ray luminosity > 10<SUP>42</SUP> erg/s. If jet-cloud
nucleosynthesis produces significant amounts of D, then the D is
either produced inside a very small nuclear region or transported
outside the nuclear region whereby subsequent infall may continuously
supply galactic nuclei with D. However, any enhanced D produced via
spallation reactions would have been destroyed via astration due to
the large AGN star formation rate. Our results are additional evidence
that D is primarily cosmological and that AGN do not produce D.
---------------------------------------------------------
Title: h Persei: Young Star Cluster in X-rays
Authors: Bizunok, Natalya; Wolk, S. J.; Evans, N. R.; Spitzbart, B.;
Seward, F.; Kenyon, S.; Barnes, T.; Pasachoff, J. M.
2005sfet.confE..48B Altcode:
We have obtained a 40 ksec ACIS observation of the open star cluster
h Per in December, 2004, from which we have identified more than 200
X-ray sources and found optical counterparts for many of them. We are
processing the h Per data with the ANCHORS pipeline, which is being used
to process Chandra observations of star forming regions in a uniform
manner. This will provide fits to the instrumental low-resolution
spectra for cool pre-main sequence stars in h Per including fluxes,
temperatures, and absorptions.
---------------------------------------------------------
Title: Spicules, mass transfer, oscillations, and the heating of
the corona
Authors: Pasachoff, J. M.; Kozarev, K. A.; Butts, D. L.; Gangestad,
J. W.; Seaton, D. B.; de Pontieu, B.; Golub, L.; Deluca, E.; Wilhelm,
K.; Dammasch, I.
2005AGUSMSH13C..02P Altcode:
The mass moving in chromospheric spicules is enough to replace the
corona in a brief time, so understanding the dynamics of spicules
is important for understanding the support and heating of the
solar corona. We have undertaken a program involving simultaneous
high-resolution observations in various chromospheric visible lines
(H-alpha, Ca II H, and G-band, as well as Dopplergrams) using the
Swedish Solar Telescope on La Palma, ultraviolet chromospheric,
transition-region, and coronal lines (Fe IX/X 171 A, Lyman-alpha
1216 A, and continuum/C I/C IV 1600 A) using NASA's TRACE, and
ultraviolet chromospheric and transition-region lines (Si II 1533,
C IV 1548, and Ne VIII 770) using SUMER on SOHO. Our first coordinated
observing run, in May 2004, yielded a variety of images that are under
study, especially for the morphological statistics and dynamics of
spicules. The energy transfer through the chromosphere is relevant to
the overlapping investigation of coronal heating through rapid (1Hz
range) oscillations of coronal loops as observed at total eclipses
by Williams College expeditions. This research is supported by NASA
grant number NNG04GK44G to Williams College. TRACE analysis at SAO
is supported by a contract from Lockheed Martin. SOHO is a project of
international cooperation between ESA and NASA.
---------------------------------------------------------
Title: The Open Cluster h Per as Seen by Chandra
Authors: Bizunok, N. S.; Evans, N. R.; Wolk, S. J.; Spitzbart, B.;
Seward, F. D.; Kenyon, S. J.; Barnes, T. G.; Pasachoff, J. M.
2005AAS...206.3604B Altcode: 2005BAAS...37R.488B
In December, 2004, we observed the open star cluster h Per with Chandra
ACIS for 40 ksec. We have identified more than 200 X-ray sources on
the image and found optical counterparts for many of them. The ANCHORS
pipeline, which we used to process the data, provides homogeneous
output products for this and many other star forming regions. Among
the outputs are fits to the instrumental low resolution spectra for
cool pre-main sequence stars in h Per that yield flux, temperature and
absorption for these sources. <P />Funding for this investigation has
been provided by Chandra contract NAS8-39073 and NASA Grant GO5-6007A
---------------------------------------------------------
Title: The black-drop effect explained
Authors: Pasachoff, Jay M.; Schneider, Glenn; Golub, Leon
2005tvnv.conf..242P Altcode: 2005IAUCo.196..242P
The black-drop effect bedeviled attempts to determine the Astronomical
Unit from the time of the transit of Venus of 1761, until dynamical
determinations of the AU obviated the need for transit measurements. By
studying the 1999 transit of Mercury, using observations taken from
space with NASA's Transition Region and Coronal Explorer (TRACE), we
have fully explained Mercury's black-drop effect, with contributions
from not only the telescope's point-spread function but also the solar
limb darkening. Since Mercury has no atmosphere, we have thus verified
the previous understanding, often overlooked, that the black-drop effect
does not necessarily correspond to the detection of an atmosphere. We
continued our studies with observations of the 2004 transit of Venus
with the TRACE spacecraft in orbit and with ground-based imagery from
Thessaloniki, Greece. We report on preliminary reduction of those
data; see http://www.transitofvenus.info for updated results. Such
studies are expected to contribute to the understanding of transits
of exoplanets. Though the determination of the Astronomical Unit from
studies of transit of Venus has been undertaken only rarely, it was
for centuries expected to be the best method. The recent 8 June 2004
transit of Venus provided an exceptionally rare opportunity to study
such a transit and to determine how modern studies can explain the
limitations of the historical observations.
---------------------------------------------------------
Title: Repeated universes in the AJP statistics literature
Authors: Pasachoff, Jay M.
2005AmJPh..73..199P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The Structure of Pluto's Atmosphere from the 2002 August 21
Stellar Occultation
Authors: Pasachoff, Jay M.; Souza, Steven P.; Babcock, Bryce A.;
Ticehurst, David R.; Elliot, J. L.; Person, M. J.; Clancy, K. B.;
Roberts, Lewis C., Jr.; Hall, D. T.; Tholen, David J.
2005AJ....129.1718P Altcode:
We have observed the 2002 August 21 occultation by Pluto of the R=15.7
mag star P131.1, using 0.5 s cadence observations in integrated white
light with the Williams College frame-transfer, rapid-readout CCD at
the 2.24 m University of Hawaii telescope. We detected an occultation
that lasted 5 minutes, 9.1+/-0.7 s between half-light points. The
“kinks” in the ingress and egress parts of the curve that were
apparent in 1988 had become much less pronounced by the time of the
two 2002 occultations that were observed, indicating a major change
in the structure of Pluto's atmosphere. Analysis of our light curves
shows that the pressure in Pluto's atmosphere has increased at all the
altitudes that we probed. Essentially, the entire pressure scale has
moved up in altitude, increasing by a factor of 2 since 1988. Spikes
in our light curve reveal vertical structure in Pluto's atmosphere at
unprecedentedly high resolution. We have confirmation of our spikes
at lower time resolution as part of observations of the emersion made
at 1.4 s and 2.4 s cadence with the 3.67 m AEOS telescope on Maui.
---------------------------------------------------------
Title: The Astronomical Unit
Authors: Pasachoff, Jay M.
2005PhTea..43...69P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The 23 November 2003 Total Solar Eclipse in Antarctica
Authors: Pasachoff, Jay M.
2005HiA....13..931P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Textbooks for K-12 Astronomy
Authors: Pasachoff, Jay M.
2005HiA....13.1048P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Astronomy Textbooks
Authors: Pasachoff, Jay M.; Pasachoff, Naomi
2005coas.conf...73P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Space Studies of the Black-Drop Effect at a Mercury Transit
Authors: Schneider, Glenn; Pasachoff, Jay M.; Golub, Leon
2005HiA....13...70S Altcode:
The accuracy with which the Astronomical Unit was known has been
historically limited by the ""black drop"" effect observed during
Venus's rare transits. It is often mistakenly attributed to Venus's
atmosphere. We report on observations taken outside the Earth's
atmosphere of the 1999 and 2003 transits of Mercury with the NASA
solar satellite known as the Transition Region and Coronal Explorer
(TRACE). Though there was no contribution from the atmosphere of Mercury
or the Earth nevertheless a faint black-drop effect was detected. We
discuss and model the images showing the sources of the black-drop
effect. The techniques we discuss are applicable to ground-based and
space-based observations of the 8 June 2004 and 5-6 June 2012 transits
of Venus.
---------------------------------------------------------
Title: The composition at the outer edge of the Galaxy
Authors: Lubowich, D. A.; Brammer, G.; Roberts, H.; Millar, T. J.;
Pasachoff, J. M.; Henkel, C.; Ruffle, P.
2005HiA....13..586L Altcode:
We present observations of a 10-Gyr-old molecular cloud at the
outer edge of the Galactic disk (28 kpc). We detected CO 13CO 18CO
CS CN SO HCN HNC HCO+ CH3OH HCS+ H2CO C2H C3H2 and NH3 but we did
not detect CO+ N2H+ DCN HC3N 34CS SiO SiS 17CO or SO2. The NH3 H2CO
and CS abundances indicate that T = 20 K and n = 5x10(3) cm(-3). The
N-containing molecules were weak and we did not detect the usually
strong N2H+ or HC3N lines. Using our 5300 chemical reaction model we
calculate that the N is depleted in this cloud by about 3x and this
cloud has a lower metallicity (similar to dwarf irregular galaxies
or damped Lyman alpha systems) and a lower cosmic-ray ionization rate
possibly resulting from the infall of halo gas enriched in O C and S
from a burst of massive star formation in the Galactic halo shortly
after the Milky Way was formed. This activity would have produced both
O and S which are produced by massive stars; C which is produced by
massive and intermediate mass stars; but less N abundance because the
secondary element N is produced primarily from low mass stars.
---------------------------------------------------------
Title: What to teach? What is learned? Astronomy as an amalgam of
new and old
Authors: Pasachoff, J. M.
2005EAS....16..137P Altcode:
The tension between contemporary astronomy and traditional topics as
subjects for general astronomy courses or fundamental science courses
is healthy, but one must worry if either type crowds out the other. Too
often only topics understood hundreds of thousands of years ago (such
as gravity, tides, phases, and seasons) take up such a large fraction
of the astronomy content that few or none of the fascinating and
important discoveries of recent centuries not to mention recent years
or months are included. I discuss aspects of this problem. Including
topics of contemporary interest often motivates students to concentrate
their attention and study time on the entire range of topics in the
course. Practitioners of the new field of Astronomy Education Research
seem often to attack their subject in perpendicular fashion to the
methods of practitioners of communicating astronomy to the public. I
also discuss some of the content of our International Astronomical
Union's Commission on Education and Development's special session
from 2003 on Effective Teaching and Learning of Astronomy, and of the
forthcoming volume of the same title to be published by Cambridge
University Press. I further discuss the role of inspiring events,
such as George Ellery Hale's inspiration from the 1882 transit of
Venus and the potential from the widespread observation of the 2004
transit of Venus and of solar eclipses.
---------------------------------------------------------
Title: Book Review: STELLAR ALCHEMY: THE CELESTIAL ORIGIN OF ATOMS /
Cambridge University Press, 2003
Authors: Pasachoff, Jay M.
2004PhT....57l..69P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Deuterium Nucleosynthesis in AGN: Is D Cosmological?
Authors: Lubowich, D. A.; Kuno, N.; Roberts, H.; Millar, T. J.;
Henkel, C.; Pasachoff, J. M.; Mauersberger, R.
2004AAS...20511807L Altcode: 2004BAAS...36Q1546L
Although deuterium is predicted to be primarily cosmological, D can
also be produced by cosmic-ray or γ -ray spallation reactions -
possibly between high energy jets and the surrounding gas in AGN. We
used the Nobeyama mm array with a 3" resolution (220 pc) in April 2003
to search for any enhanced D from the DCN J = 2-1 line in the Seyfert
galaxy NGC 1068. NGC 1068 is an optimal target because it has jets,
starburst activity, a circumuclear molecular ring and disk, dense
optically thick concentrations of HCN, and a low-energy X-ray flux
of 10<SUP>42</SUP> erg/s (the highest X-ray flux of any galaxy in
which HCN has been detected and the flux required to produce high D
abundances). We did not detect DCN (which is detected in all other
molecular clouds with optically thick HCN in the Galaxy or LMC)
and we obtained an upper limit of S≤15 mJy/beam = 48.5 mK in the
circumnuclear region and a DCN/HCN ratio of 0.0046. Using our 5300
reaction chemical network we estimate D/H leq1.5x10<SUP>-5</SUP>
as compared to the local Galactic ISM D/H = 1.4x10<SUP>-5</SUP>. <P
/>Thus there is no significant D production in the nuclear region of
NGC 1068 and NGC 1068 has probably not had a recent period of activity
with a γ -ray or cosmic-ray luminosity > 10<SUP>42</SUP> erg/s. If
jet-cloud nucleosynthesis produces significant amounts of D, then the
D is produced outside of the nuclear region where the subsequent infall
may be one way to continuously supply galactic nuclei with D. However,
any enhanced D produced via spallation reactions would have been
destroyed via astration due to the faster star formation rate. Our
results are additional evidence that D is primarily cosmological and
that AGN do not produce D.
---------------------------------------------------------
Title: The Effect of the Transit of Venus on ACRIM's Total Solar
Irradiance Measurements: Implications for Transit Studies of
Extrasolar Planets
Authors: Pasachoff, J. M.; Schneider, G.; Willson, R. C.
2004AAS...20513511P Altcode: 2004BAAS...36.1566P
We used 131-s-cadence observations made with ACRIM3 on ACRIMsat on 8
June 2004 to follow the effect of the transit of Venus, which lasted
about 6 hours, on the total solar irradiance (TSI). Venus's angular
diameter, in transit, is approximately 1/30 the solar diameter, so
it covered approximately 0.1% of the sun's surface. With our ACRIM3
data, we measure temporal changes in TSI with a one-sigma per sample
(unbinned) certainty of approximately 100 milliwatts per square
meter (0.007%). We found a diminution in TSI of approximately 1.4
watts per square meter (approximately 0.1%, closely corresponding to
the geometrically occulted area of the photosphere) at mid-transit
compared with a mean pre/post transit TSI of 1365.9 watts per square
meter. The measured light curve is complex because of the parallactic
motion of Venus induced by the satellite's polar orbit, but exhibits
the characteristic signature of photospheric limb-darkening when
orbit-driven variations are accounted for. Analysis of the limb
darkening can reveal temporal structure with height in the photosphere
and asymmetries can, in principle, be attributable to planetary
atmospheres. Similar observations will increasingly be detected from
exoplanet transits, so detailed analysis of the transit within our solar
system will provide a useful analogue for interpreting the many more
such transits expected to be discovered within the next decade. <P
/>JMP's and GS's transit of Venus observations were supported by a
grant from the Committee for Research and Exploration of the National
Geographic Society. NASA provides support for RCW at Columbia University
under contract NNG04HZ42C.
---------------------------------------------------------
Title: Stellar Alchemy: The Celestial Origin of Atoms
Authors: Cassé, Michel; Lyle, Stephen; Pasachoff, Jay M.
2004PhT....57l..69C Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Satellite and Ground-Based Observations of the Transit of Venus
Authors: Pasachoff, J. M.; Schneider, G.; Babcock, B. A.; Butts,
D. L.; Gangestad, J. W.; Westbrook, O. W.; Cordova, A. R.; Gaydosh,
K.; Seiradakis, J. H.
2004DPS....36.3901P Altcode: 2004BAAS...36.1161P
We report on a coordinated program of CCD observations of the transit
of Venus of 8 June 2004 made with NASA's Transition Region and Coronal
Explorer (TRACE) spacecraft and with ground-based observations from
Greece (including the first two contacts) and the U.S. (the last
two contacts). We observed in white light, with special attention to
imaging Venus's atmosphere at ingress and egress and to the presence
and formation of the black-drop effect at second and third contacts. We
analyze the data in terms of the telescope's point-spread function,
the solar limb darkening (which we previously showed to have a role
in the black-drop effect for a transit of Mercury), and seeing effects
from the terrestrial atmosphere. Our TRACE data have a 7-s cadence at
uncompressed data transmission and higher for compressed data, both
over the 20-min ingress and egress phases. <P />Our expedition was
supported by a grant from the Committee for Research and Exploration
of the National Geographic Society. We thank Sigma Xi for additional
student support.
---------------------------------------------------------
Title: Box: Transit Research in the 21st Century
Authors: Pasachoff, Jay M.
2004S&T...108e..82P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Fascinating Pluto
Authors: Pasachoff, Jay M.; Elliot, James L.
2004PhT....57i..18P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: TRACE observations of the 15 November 1999 transit of Mercury
and the Black Drop effect: considerations for the 2004 transit
of Venus
Authors: Schneider, Glenn; Pasachoff, Jay M.; Golub, Leon
2004Icar..168..249S Altcode:
Historically, the visual manifestation of the "Black Drop effect," the
appearance of a band linking the solar limb to the disk of a transiting
planet near the point of internal tangency, had limited the accuracy of
the determination of the Astronomical Unit and the scale of the Solar
System in the 18th and 19th centuries. This problem was misunderstood
in the case of Venus during its rare transits due to the presence of
its atmosphere. We report on observations of the 15 November 1999
transit of Mercury obtained, without the degrading effects of the
Earth's atmosphere, with the Transition Region and Coronal Explorer
spacecraft. In spite of the telescope's location beyond the Earth's
atmosphere, and the absence of a significant mercurian atmosphere, a
faint Black Drop effect was detected. After calibration and removal of,
or compensation for, both internal and external systematic effects,
the only radially directed brightness anisotropies found resulted
from the convolution of the instrumental point-spread function with
the solar limb-darkened, back-lit, illumination function. We discuss
these effects in light of earlier ground-based observations of transits
of Mercury and of Venus (also including the effects of atmospheric
"seeing") to explain the historical basis for the Black Drop effect. The
methodologies we outline here for improving upon transit imagery are
applicable to ground-based (adaptive optics augmented) and space-based
observations of the 8 June 2004 and 5-6 June 2012 transits of Venus,
providing a path to achieving high-precision measurements at and near
the instants of internal limb tangencies.
---------------------------------------------------------
Title: The Chemical Composition of a Molecular Cloud at the Outer
Edge of the Galaxy
Authors: Lubowich, D. A.; Brammer, G.; Roberts, H.; Millar, T. J.;
Henkel, C.; Pasachoff, J. M.
2004oee..sympE..37L Altcode:
Centimeter and millimeter-wave observations of a molecular cloud at
the extreme outer edge of the Galactic disk (kinematic ga lactocentric
distance: ∼28 kpc) are presented. We detected CO, <SUP>13</SUP>CO,
<SUP>18</SUP>CO, CS, CN, SO, HCN, HNC, C<SUB>2</SUB>H, HCO<SUP>+</SUP>,
H<SUP>13</SUP>CO<SUP>+</SUP>, HCS<SUP>+</SUP>, NH<SUB>3</SUB>,
H<SUB>2</SUB>CO, C<SUB>3</SUB>H<SUB>2</SUB> and CH<SUB>3</SUB>OH, while
<SUP>17</SUP>CO, <SUP>34</SUP>CS, SiO, SiS, N<SUB>2</SUB>H<SUP>+</SUP>,
D CN, DNC, DCO<SUP>+</SUP>, SO<SUB>2</SUB> and HC<SUB>3</SUB>N remained
undetected. From the NH<SUB>3</SUB> and H<SUB>2</SUB>CO data, a kinetic
temperature of T<SUB>kin</SUB> ∼20 K and a density of n(H<SUB>2</SUB>)
∼5×10<SUP>3</SUP> cm<SUP>-3</SUP> are derived. Nitrogen bearing
molecules show , when detected, only weak lines. Commonly strong
line emitters such as N<SUB>2</SUB>H<SUP>+</SUP> and HC<SUB>3</SUB>N
were not seen. Using a numeri cal network including 5300 chemical
reactions we determined that N is depleted by approximately 24 times,
and the metallicit y is reduced by a factor of five (similar to dwarf
irregular galaxies or damped Lyman alpha systems) relative to the
solar ne ighborhood. These unusual abundances are probably the result
of the infall of halo gas enriched in O, C, and S from a burst o f
massive star formation in the Galactic halo shortly after the Milky
Way was formed. This activity would have produced both O and S, which
are produced by massive stars; C, which is produced by massive and
intermediate mass stars; but less N abundan ce because the secondary
element N is produced primarily from low mass stars. Thus the edge cloud
probably results from infal ling halo gas from the early Galaxy that was
not significantly processed during the last 10 Gyr and provides a new
way to und erstand the origin of the Galactic disk. Our observations
of the early Galactic disk abundances will constrain models of nu
cleosynthesis, Galactic chemical evolution, and astrochemistry.
---------------------------------------------------------
Title: The Bohr Staircase
Authors: Pasachoff, Jay M.
2004PhTea..42...38P Altcode:
The attempt to bring students to critical thinking about topics in
contemporary astronomy is a goal shared by many teachers. Since the
rise of astrophysics in the early 20th century, spectroscopy has been
the defining technique. Various techniques have been tried to give
students a concrete understanding of emission lines and absorption
lines in the hydrogen spectrum.1 Spectroscopy of hydrogen plays an
important part of most textbooks in elementary astronomy.2 After years
of jumping off lecture-room steps and trying (but never succeeding) in
hovering between stair levels, I still find too many students drawing
equally spaced hydrogen energy levels on exams. I thus arranged for
carpenters to build a five-step staircase with the spacing matching
that of the actual hydrogen energy levels. I can now use the staircase
to demonstrate the Bohr atom3 in a memorable manner. “Bohr staircase”
is therefore a suitable name for it. If a teacher wants to stress the
visible spectrum rather than the energy levels, “Balmer staircase”
is an alternate name.
---------------------------------------------------------
Title: Explanation of the Black-Drop Effect at Transits of Mercury
and the Forthcoming Transit of Venus
Authors: Pasachoff, J. M.; Schneider, G.; Golub, L.
2003AAS...203.0104P Altcode: 2003BAAS...35.1202P
We used the observations of the transits of Mercury of 1999 and 2003
taken with NASA's Transition Region and Coronal Explorer (TRACE) solar
spacecraft. For the 1999 Mercury transit, for which data were acquired
with the highest digital fidelity available for TRACE, we detected a
black-drop effect, in spite of the facts that we were observing from
outside the Earth's atmosphere and that Mercury has no significant
atmosphere. We were able to show that the Mercury black-drop effect
comes from a convolution of the instrument's point-spread function and
the solar limb darkening. By implication, we should be able to explain
Venus's black-drop effect in a similar way. It has long been known that
Venus's black-drop effect is too large to come from Venus's atmosphere.
---------------------------------------------------------
Title: Rowling Gets It Wrong
Authors: Pasachoff, Jay M.
2003S&T...106f..12P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The Value of the Great Observatories' Educational Programs
Authors: Pasachoff, J. M.
2003AAS...20310701P Altcode: 2003BAAS...35.1376P
What should non-major and school-level students learn about
astronomy? The current trend in Physics Education Research, now being
translated to Astronomy Education Research, is that "less is more." As
a result, there may be little time for modern topics or there may be a
judgment that these topics are too abstract to teach. <P />Yet NASA's
Great Observatories and other missions have vital and interesting
Education and Public Outreach programs. Through the Web, through
distribution of CD-ROM's and other media, and through a variety of
materials and activities these programs provide not only reports on
current research but also substantial background information. <P />To
explore the contemporary question of what we professional astronomers
think we should be communicating to students at all levels, I have
invited both scientists and public information officers of the Hubble
Space Telescope, the Chandra X-ray Observatory, and the Space Infrared
Telescope Facility to discuss the importance and the methodologies of
their Education and Public Outreach programs.
---------------------------------------------------------
Title: Book review: The enigma of sunspots: a story of discovery
and scientific revolution / Floris Books, Edinburgh, 192 pp., 2002,
ISBN 0-86315-370-4.
Authors: Pasachoff, Jay M.
2003JHA....34..458P Altcode: 2003JHA....34..458B
No abstract at ADS
---------------------------------------------------------
Title: Feeling a Bit Green?
Authors: Pasachoff, Jay M.
2003S&T...106d..16P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Space Studies of the Black-Drop Effect at a Mercury Transit
Authors: Schneider, G.; Pasachoff, J. M.; Golub, L.
2003astro.ph.10379S Altcode:
Transits of Mercury and Venus across the face of the Sun are rare. The
20th century had 15 transits of Mercury and the 21st century will have
14, the two most recent occuring on 15 November 1999 and 7 May 2003. We
report on our observations and analyses of a black-drop effect at the
1999 and 2003 transits of Mercury seen in high spatial resolution
optical imaging with NASA's Transition Region and Coronal Explorer
(TRACE) spacecraft. We have separated the primary contributors to this
effect, solar limb darkening and broadening due to the instrumental
point spread function, for the 1999 event. The observations are
important for understanding historical observations of transits
of Venus, which in the 18th and 19th centuries were basic for the
determination of the scale of the solar system. Our observations
are in preparation for the 8 June 2004 transit of Venus, the first
to occur since 1882. Only five transits of Venus have ever been seen
-- in 1639, 1761, 1769, 1874, and 1882. These events occur in pairs,
whose members are separated by 8 years, with an interval between pairs
of 105 or 122 years. Nobody alive has ever seen a transit of Venus.
---------------------------------------------------------
Title: The Complete Idiot's Guide to The Sun
Authors: Pasachoff, Jay M.
2003cigs.book.....P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The recent expansion of Pluto's atmosphere
Authors: Elliot, J. L.; Ates, A.; Babcock, B. A.; Bosh, A. S.; Buie,
M. W.; Clancy, K. B.; Dunham, E. W.; Eikenberry, S. S.; Hall, D. T.;
Kern, S. D.; Leggett, S. K.; Levine, S. E.; Moon, D. -S.; Olkin, C. B.;
Osip, D. J.; Pasachoff, J. M.; Penprase, B. E.; Person, M. J.; Qu,
S.; Rayner, J. T.; Roberts, L. C.; Salyk, C. V.; Souza, S. P.; Stone,
R. C.; Taylor, B. W.; Tholen, D. J.; Thomas-Osip, J. E.; Ticehurst,
D. R.; Wasserman, L. H.
2003Natur.424..165E Altcode:
Stellar occultations-the passing of a relatively nearby body in front
of a background star-can be used to probe the atmosphere of the closer
body with a spatial resolution of a few kilometres (ref. 1). Such
observations can yield the scale height, temperature profile, and other
information about the structure of the occulting atmosphere. Occultation
data acquired for Pluto's atmosphere in 1988 revealed a nearly
isothermal atmosphere above a radius of ~1,215km. Below this level,
the data could be interpreted as indicating either an extinction
layer or the onset of a large thermal gradient, calling into question
the fundamental structure of this atmosphere. Another question is to
what extent Pluto's atmosphere might be collapsing as it recedes from
the Sun (passing perihelion in 1989 in its 248-year orbital period),
owing to the extreme sensitivity of the equilibrium surface pressure to
the surface temperature. Here we report observations at a variety of
visible and infrared wavelengths of an occultation of a star by Pluto
in August 2002. These data reveal evidence for extinction in Pluto's
atmosphere and show that it has indeed changed, having expanded rather
than collapsed, since 1988.
---------------------------------------------------------
Title: Pluto's Atmospheric Figure from the P131.1 Stellar Occultation
Authors: Person, M. J.; Elliot, J. L.; Clancy, K. B.; Kern, S. D.;
Salyk, C. V.; Tholen, D. J.; Pasachoff, J. M.; Babcock, B. A.; Souza,
S. P.; Ticehurst, D. R.; Hall, D.; Roberts, L. C., Jr.; Bosh, A. S.;
Buie, M. W.; Dunham, E. W.; Olkin, C. B.; Taylor, B.; Levine, S. E.;
Eikenberry, S. S.; Moon, D. -S.; Osip, D. J.
2003DPS....35.2301P Altcode: 2003BAAS...35..957P
The stellar occultation by Pluto of the 15th magnitude star designated
P131.1 (McDonald and Elliot, AJ, 119, 1999) on 2002 August 21 (UT)
provided the first significant chance to compare Pluto's atmospheric
structure to that determined from the 1988 occultation of P8 (Millis,
et al., Icarus, 105, 282). The P131.1 occultation was observed from
several stations in Hawaii and the western United States (Elliot
et al., Nature, in press, 2003). Numerous occultation chords were
obtained enabling us to examine Pluto's atmospheric figure. The light
curves from the observations were analyzed together in the occultation
coordinate system of Elliot et al., (AJ, 106, 2544). The Mauna Kea
and Lick datasets straddle the center of Pluto's figure, providing
strong constraints on model fits to cross sections of the atmospheric
shape. <P />In 1988, Millis (et al., Icarus, 105, 282) did not report
any deviation from sphericity in Pluto's atmospheric figure. From the
2002 data, Pluto;s isobars at the radii probed by the occultation ( 1250
km) appear to be distorted from a circular cross-section. Least-squares
fits to this cross-section by elliptical models reveal ellipticities
in the range 0.05-0.08 although the shape may be more complex than
ellipsoidal. The orientation of the distortion appears uncorrelated
with Pluto;s rotational axis. Taken at face value, this ellipticity
could imply wind speeds of up to twice the sonic speed ( 200 m/s),
which would be difficult to explain. Similar distortions have been
reported for Triton's atmosphere (Elliot, J. L., et al., Icarus 148,
347). This work has been supported in part by Research Corporation,
the Air Force Research Laboratory, NSF, and NASA.
---------------------------------------------------------
Title: Book Review: Setting sail for the universe: astronomers
and their discoveries / Rutgers University Press, Piscataway, NJ,
192 pp., 2002, ISBN 0-8135-3088-1.
Authors: Pasachoff, Jay M.
2003JHA....34..238P Altcode: 2003JHA....34..238F
No abstract at ADS
---------------------------------------------------------
Title: Working Group on Solar Eclipses (Groupe de Travail pour les
Eclipses Solaires)
Authors: Pasachoff, Jay M.
2003IAUTA..25...75P Altcode: 2003IAUTr..25A..75P
No abstract at ADS
---------------------------------------------------------
Title: What Should Students Learn? Stellar Magnitudes?
Authors: Pasachoff, Jay M.
2003AEdRv...2b.162P Altcode: 2003AEdRv...2..162P
No abstract at ADS
---------------------------------------------------------
Title: Textbooks for K-12 Astronomy
Authors: Pasachoff, Jay M.
2003IAUSS...4E..63P Altcode:
Astronomy is a part of the science curriculum of the early years of
K-12 education in the United States but after a grades 7-9 (ages
13-15 approximately) sequence that is usually Life Sciences/Earth
Sciences/Physical Sciences no science is commonly required. Several
national projects have addressed the astronomy content of K-12
education. I will discuss and show examples of the astronomy content
in American school textbooks and various of the proposals that have
been advanced for reform.
---------------------------------------------------------
Title: The 23 November 2003 Total Solar Eclipse in Antarctica
Authors: Pasachoff, Jay M.
2003IAUSS...2E...9P Altcode:
The total solar eclipse of 23 November 2003 will be visible only
from Antarctica. The path of totality extends from Mirny at 93°E
to the Maitri Novolazarevskaya 12°E. Totality lasts from 1 minute
54 seconds at Mirny with the Sun at an altitude of 14° to a maximum
of 1 minute 57 seconds at greatest eclipse halfway in toward Vostok
with the Sun at an altitude of 18° to 1 minute 20 s with the Sun 2°
above the horizon where the path leaves the coast near Maitri. The
rest of Antarctica will have only a partial eclipse with the Sun's
diameter 77% covered at McMurdo and 65° covered at the tip near
South America. An icebreaker passenger ship is planning a 28-day
voyage and airplanes are being arranged for observation. Scientific
observations will include electronic imaging of the corona to compare
with simultaneous space observations of the Sun. Links to maps and
other items of coordination can be found at www.eclipses.info and
www.totalsolareclipse.net the sites of the IAU Program Group on Public
Education at the Time of Eclipses and of the IAU Working Group on
Eclipses respectively. The NASA site with maps and other information
is at sunearth.gsfc.nasa.gov/eclipse/TSE2003/TSE2003.html
---------------------------------------------------------
Title: Space Studies of the Black Drop Effect at a Mercury Transit
Authors: Pasachoff, Jay M.; Schneider, Glenn; Golub, Leon
2003IAUJD...2E...5P Altcode:
The accuracy with which the Astronomical Unit was known has been
historically limited by the ""black drop"" effect observed during
Venus's rare transits. It is often mistakenly attributed to Venus's
atmosphere. We report on observations taken outside the Earth's
atmosphere of the 1999 and 2003 transits of Mercury with the NASA
solar satellite known as the Transition Region and Coronal Explorer
(TRACE). Though there was no contribution from the atmosphere of Mercury
or the Earth nevertheless a faint black-drop effect was detected. We
discuss and model the images showing the sources of the black-drop
effect. The techniques we discuss are applicable to ground-based and
space-based observations of the 8 June 2004 and 5-6 June 2012 transits
of Venus.
---------------------------------------------------------
Title: The Composition at the Outer Edge of the Galaxy
Authors: Lubowich, Donald; Brammer, Gabriel; Roberts, Helen; Millar,
Tom; Henkel, Christian; Pasachoff, Jay; Ruffle, Paul
2003IAUJD..15E..51L Altcode:
We present observations of a 10-Gyr-old molecular cloud at the
outer edge of the Galactic disk (28 kpc). We detected CO 13CO 18CO
CS CN SO HCN HNC HCO+ CH3OH HCS+ H2CO C2H C3H2 and NH3 but we did
not detect CO+ N2H+ DCN HC3N 34CS SiO SiS 17CO or SO2. The NH3 H2CO
and CS abundances indicate that T = 20 K and n = 5x10(3) cm(-3). The
N-containing molecules were weak and we did not detect the usually
strong N2H+ or HC3N lines. Using our 5300 chemical reaction model we
calculate that the N is depleted in this cloud by about 3x and this
cloud has a lower metallicity (similar to dwarf irregular galaxies
or damped Lyman alpha systems) and a lower cosmic-ray ionization rate
possibly resulting from the infall of halo gas enriched in O C and S
from a burst of massive star formation in the Galactic halo shortly
after the Milky Way was formed. This activity would have produced both
O and S which are produced by massive stars; C which is produced by
massive and intermediate mass stars; but less N abundance because the
secondary element N is produced primarily from low mass stars.
---------------------------------------------------------
Title: The forgotten star atlas : John Bevis's Uranographia
Britannica.
Authors: Kilburn, K. J.; Pasachoff, J. M.; Gingerich, O.
2003JHA....34..125K Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Back to School
Authors: Pasachoff, Jay M.
2003S&T...105a..12P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Committee of Ten and Astronomy
Authors: Pasachoff, Jay M.
2002PhTea..40..517P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Pluto Occultation of P131.1 in 2002 August: Overview of
Observations and Infrared Results
Authors: Elliot, J. L.; Clancy, K. B.; Rayner, J. T.; Tholen,
D. J.; Person, M. J.; Osip, D. J.; Pasachoff, J. M.; Babcock,
B. A.; Ticehurst, D. R.; Hall, D.; Roberts, L. C., Jr.; Bosh, A. S.;
Eikenberry, S. S.; Moon, D. -S.; Buie, M. W.; Dunham, E. W.; Olkin,
C. B.; Taylor, B.; Kern, S. D.; Qu, S.; Salyk, C. V.; Leggett, S. K.;
Levine, S. E.; Stone, R. C.
2002AAS...201.6101E Altcode: 2002BAAS...34.1211E
Pluto's occultation of the star P131.1 (R = 15.7, K = 13.3; see McDonald
& Elliot, 2002, AJ 120, 1599) on 2002 August 21 was successfully
observed with nine telescopes: the IRTF, UH 2.2m, UH 0.6m, UKIRT, and
CFHT on Mauna Kea; the AEOS telescope on Haleakala, the Shane telescope
at Lick Observatory, the Perkins telescope at Lowell Observatory, and
the Hale telescope at Palomar Observatory. Occultation light curves were
recorded at a variety of time resolutions and wavelengths in order to
facilitate several investigations of Pluto's atmosphere (see Pasachoff
et al., Person et al., Clancy et al., this meeting). We confirm the
main conclusion from the P126 occultation (Buie et al., BAAS 34, 877)
that the structure of Pluto's atmosphere has changed substantially
since it was last observed in 1988 (Elliot & Young et al., AJ 103,
991). The multi-wavelength nature of our P131.1 data set allows us to
elucidate these changes. The IRTF data were recorded with SpeX (Rayner
et al. 2003 PASP, in preparation) and span the 0.8 to 2.5 micron region
of the spectrum. Although recorded at lower time resolution (about 4
spectra per minute) than the other data sets, comparison of the SpeX
light curves at different wavelengths (and comparing them with the
visible light curves) is being used to establish the role of extinction
by possible hazes and clouds in Pluto's atmosphere throughout the
occultation. These IR data and the UKIRT light curve with the H filter
will be used to correct the visible-light curves for extinction effects
(if present) prior to inverting the light curves to obtain temperature,
pressure, and number-density profiles of Pluto's atmosphere. This work
has been supported in part by Research Corporation, NASA, and NSF.
---------------------------------------------------------
Title: High-Time-Resolution White-Light Observations of Pluto's
Occultation of P131.1 in 2002 August
Authors: Pasachoff, J. M.; Elliot, J. L.; Babcock, B. A.; Ticehurst,
D. R.; Tholen, D. J.; Person, M. J.
2002AAS...201.6102P Altcode: 2002BAAS...34Q1211P
We observed a 304-s FWHM occultation of the 15th magnitude (R) star
P131.1 by Pluto on 2002 August 21 (UT) with the University of Hawaii's
2.2-m telescope on Mauna Kea. We used a Princeton Instruments/Roper
front-illuminated CCD in frame-transfer mode at a 0.5 s cadence, with no
filter in order to maximize the signal-to-noise ratio. Seeing was 0.4
arcsec; Charon was distinctly visible throughout alongside Pluto. We
obtained images with our 0.2 arcsec pixels for astrometric purposes
at various times before and after the occultation on the night of the
occultation and on the preceding night. In our occultation run of 20
min, we binned 5x5 and obtained 2400 images. A nearby double star
allowed monitoring of the sky transparency. The light curve shows
the occultation at a higher cadence than the visible and infrared
light curves obtained at adjacent telescopes. We discuss the fully
reduced and calibrated light curve, the implications for models of
haze in Pluto's atmosphere from the lack of complete occultation
even at full depth, and the interpretation of positive spikes in
the light curve during the emersion as waves or turbulence in Pluto's
atmosphere. We compare these white-light observations with the infrared
results obtained simultaneously and discuss implications for Pluto's
current atmospheric structure. This work was supported by Research
Corporation, by NASA through its New Horizons project, and by Williams
College. The CCD is part of NSF-supported solar-eclipse research. We
thank A. Pickles for assistance with scientific arrangements at Mauna
Kea and S. P. Souza for help with preliminary data reduction and other
aspects of the expedition.
---------------------------------------------------------
Title: Examination of Pluto's Atmospheric Figure with the P131.1
Stellar Occultation
Authors: Person, M. J.; Elliot, J. L.; Clancy, K. B.; Tholen, D. J.;
Rayner, J. T.; Pasachoff, J. M.; Babcock, B. A.; Ticehurst, D. R.;
Hall, D.; Roberts, L. C., Jr.; Bosh, A. S.; Eikenberry, S. S.; Moon,
D. S.; Buie, M. W.; Dunham, E. W.; Olkin, C. B.; Taylor, B.; Kern,
S. D.; Osip, D. J.; Qu, S.; Salyk, C. V.; Leggett, S. K.; Levine,
S. E.; Stone, R. C.
2002AAS...201.6103P Altcode: 2002BAAS...34R1211P
From the 1988 stellar occultation by Pluto, Millis (et al., Icarus,
105, 282) did not report any deviation from sphericity in Pluto's
atmospheric figure. However, stellar occultation measurements of Triton
throughout the late 1990's revealed a significant deviation from a
spherical figure in Triton's atmospheric shape (Elliot et al., Icarus,
148, 347, and Person 2001, S.M. Thesis, Dept. of Earth Atmos. and
Plan. Sci., Mass. Inst. Of Tech., Cambridge MA). This deviation is
unexpected since Triton's rotation period is slow (5.88 days), but
the resulting non-spherical shape could be due to high winds. The
Triton results have prompted us to examine Pluto's atmospheric figure
with more recent data. The stellar occultation by Pluto of the 15th
magnitude star designated P131.1 (McDonald and Elliot, AJ, 119,
1999) on 2002 August 21 (UT) provided the first significant chance
since the Triton results to measure such non-sphericity in Pluto's
atmosphere. The occultation was observed from numerous stations in
Hawaii and the western United States (see Elliot et al., Pasachoff
et al., Clancy et al., this conference). We present the results
of our analysis of these datasets in searching for non-spherical
deviations in Pluto's atmospheric figure. The light curves from the
observations were analyzed together in the occultation coordinate
system of Elliot et al., (AJ, 106, 2544). The datasets from the various
Mauna Kea telescopes are redundant with each other in figure space,
but provide valuable cross checks among their timing systems. The
Mauna Kea and Lick datasets straddle the center of Pluto's figure,
providing strong constraints on model fits to cross sections of the
atmospheric shape. As a second measure of possible non-sphericity,
the individual light curves can be individually fit with atmospheric
models in the manner of Elliot and Young (AJ, 103, 991), to search
for asymmetry indicative of a non-circular atmospheric cross section
around the limb of the planet. This work has been supported in part
by Research Corporation, NASA, and NSF.
---------------------------------------------------------
Title: Comets, meteors, and eclipses: Art and science in early
Renaissance Italy
Authors: Olson, R. J. M.; Pasachoff, J. M.
2002M&PS...37.1563O Altcode:
We discuss eight trecento (fourteenth century) paintings containing
depictions of astronomical events to reveal the revolutionary advances
made in both astronomy and naturalistic painting in early Renaissance
Italy, noting that an artistic interest in naturalism predisposed these
pioneering painters to make their scientific observations. In turn,
the convincing representations of their observations of astronomical
phenomena in works of art rendered their paintings more believable,
convincing. Padua was already a renowned center for mathematics
and nascent astronomy (which was separating from astrology) when
Enrico Scrovegni commissioned the famous Florentine artist Giotto di
Bondone to decorate his lavish family chapel (circa 1301-1303). Giotto
painted a flaming comet in lieu of the traditional Star of Bethlehem
in the Adoration of the Magi scene. Moreover, he painted a historical
apparition that he recently had observed with a great accuracy even
by modern standards. Halley's Comet of 1301 (Olson, 1979). While we do
not know the identity of the artist's theological advisor, we discuss
the possibility that Pietro d'Abano, the Paduan medical doctor and
"astronomer" who wrote on comets, might have been influential. We
also compare Giotto's blazing comet with two others painted by the
artist's shop in San Francesco at Assisi (before 1316) and account
for the differences. In addition, we discuss Giotto's pupil, Taddeo
Gaddi, reputed to have been partially blinded by a solar eclipse,
whose calamity may find expression in his frescoes in Santa Croce,
Florence (1328-30; 1338?). Giotto also influenced the Sienese painter
Pietro Lorenzetti, two of whose Passion cycle frescoes at Assisi
(1316-20) contain dazzling meteor showers that reveal the artist's
observed astronomical phenomena, such as the "radiant" effect of meteor
showers, first recorded by Alexander von Humboldt in 1799 and only
accepted in the nineteenth century. Lorenzetti also painted sporadic,
independent meteors, which do not emanate from the radiant. It is also
significant that these artists observed differences between comets and
meteors, facts that were not absolutely established until the eighteenth
century. In addition we demonstrate that artistic and scientific visual
acuity were part of the burgeoning empiricism of the fourteenth century,
which eventually yielded modern observational astronomy.
---------------------------------------------------------
Title: Haystack radio telescope
Authors: Pasachoff, Jay M.
2002AmJPh..70..983P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Changes in Pluto's Atmosphere Revealed by the P126A Occultation
Authors: Buie, M. W.; Elliot, J. L.; Kidger, M. R.; Bosh, A. S.;
Saá, O.; Van Malderen, R.; Uytterhoeven, K.; Davignon, G.; Dunham,
E. W.; Olkin, C. B.; Taylor, B. W.; Wasserman, L. H.; Clancy, K.;
Person, M. J.; Levine, S. E.; Stone, R. C.; Peréz-González, P. G.;
Pasachoff, J. M.; Souza, S. P.; Ticehurst, D. R.; Fitzsimmons, A.
2002DPS....34.2102B Altcode: 2002BAAS...34..877B
We will report the results from an occultation of P126A by
Pluto on the night of 2002 July 20 UT. The event was successfully
observed with a 0.4-m telescope at Mamiña, Chile under photometric
conditions. Additional data were collected at CTIO on a 0.6-m telescope
with heavy interference from clouds. The CTIO observations preclude an
occultation at that location thus forcing the Mamiña chord to lie south
of the centerline. Less-constraining negative results were obtained
from the Canary Islands. The Mamiña lightcurve shows an occultation
profile that clearly indicates the continued presence of a substantial
atmosphere around Pluto. The profile does not show any trace of the
“kink” seen in the 1988 occultation data at a similar distance
from the centerline of the shadow. Depending on the specific model
assumptions, the minimum distance of Mamiña from the center of Pluto's
shadow lies in the range 1025-1130 km, which corresponds to a range of
1180-1260 km for the deepest radius probed in Pluto's atmosphere. These
new occultation data cannot be well fitted with models derived from the
1988 data. Hence one or more changes have occurred in Pluto's atmosphere
in the past 14 years. Either the haze/thermal gradient altitude has
decreased (or disappeared altogether), or the temperature above this
level has increased (accompanied by an increase in pressure), or some
combination of the these two. These results challenge the current
level of understanding of the nature of Pluto's atmosphere and its
surface-atmosphere interaction. This work was supported, in part, by
NASA Grants NAG5-10444, NAG5-9008, by NOAO and CTIO operated for NSF by
AURA, NASA through the New Horizons project, and Research Corporation.
---------------------------------------------------------
Title: Short-Period Waves That Heat the Corona Detected at the
1999 Eclipse
Authors: Pasachoff, Jay M.; Babcock, Bryce A.; Russell, Kevin D.;
Seaton, Daniel B.
2002SoPh..207..241P Altcode: 2002astro.ph..2237P
As a part of a study of the cause of solar coronal heating, we
searched for high-frequency (∼ 1 Hz) intensity oscillations in
coronal loops in the [Fe xiv] coronal green line. We summarize results
from observations made at the 11 August 1999 total solar eclipse from
Râmnicu-Vâlcea, Romania, through clear skies. We discuss the image
reduction and analysis through two simultaneous series of coronal
CCD images digitized at 10 Hz for a total time of about 140 s. One
series of images was taken through a 3.6 Å filter isolating the 5303
Å[Fe xiv] coronal green line and the other through a 100 Å filter
in the nearby K-corona continuum. Previous observations, described in
Pasachoff et al. (2000), showed no evidence for oscillations in the
[Fe xiv] green line at a level greater than 2% of coronal intensity. We
describe several improvements made over the 1998 eclipse that led to
increased image clarity and sensitivity. The corona was brighter in
1999 with the solar maximum, further improving the data. We use Fourier
analysis to search in the [Fe xiv] channel for intensity oscillations
in loops at the base of the corona. Such oscillations in the 1-Hz range
are predicted as a result of density fluctuations from the resonant
absorption of MHD waves. The dissipation of a significant amount
of mechanical energy from the photosphere into the corona through
this mechanism could provide sufficient energy to heat the corona. A
Monte Carlo model of the data suggests the presence of enhanced power,
particularly in the 0.75-1.0 Hz range, and we conclude that MHD waves
remain a viable method for coronal heating.
---------------------------------------------------------
Title: Further Analysis of Short-Period Waves for Coronal Heating
from the 1999 Eclipse
Authors: Seaton, D. B.; Pasachoff, J. M.; Babcock, B. A.; Russell,
K. D.
2002AAS...200.8804S Altcode: 2002BAAS...34..789S
As a part of a study of the cause of solar coronal heating, we searched
at several eclipses for high-frequency ( 1 Hz) intensity oscillations
in coronal loops in the [Fe XIV] coronal green line. Such oscillations
in the 1-Hz range are predicted as a result of density fluctuations
from the resonant absorption of MHD waves. The dissipation of a
significant amount of mechanical energy from the photosphere into
the corona through this mechanism could provide sufficient energy to
hear the corona. We summarize results from observations made at the
11 August 1999 total solar eclipse from Râmnicu-Vâlcea, Romania,
through clear skies, where data were taken through two simultaneous
series of coronal CCD images digitized at 10 Hz for a total time of
about 140 s. Previous observations, described in Pasachoff, Babcock,
Russell, McConnochie, and Diaz (2000), had a detection limit of 2% for
intensity oscillations in the [Fe XIV] green line. We found stronger
coronal intensity at the 1999 eclipse because of the peak in the sunspot
cycle and we selected our region of observations in consultation with
SOHO/EIT and TRACE scientists. One series of images was taken through
a 3.6 Å filter isolating the 5303 Å [Fe XIV] coronal green line and
the other through a 100 Å filter in the nearby K-corona continuum. We
used Fourier analysis to search in the [Fe XIV] channel for intensity
oscillations in loops at the base of the corona (Pasachoff, Babcock,
Russell, & Seaton, 2002). A comparison with a Monte-Carlo model of
the data suggested the presence of enhanced power, particularly in the
0.75-1.0 Hz range. We report on our ongoing wavelet analysis that may
make a stronger case for the presence of oscillations in our data. We
also discuss plans for observing the 4 December 2002 eclipse. Support
for this research has been provided by the National Science Foundation,
the National Geographic Society, and NASA; DBS is supported by the
TRACE grant, contract NAS5-38099 from NASA to LMATC.
---------------------------------------------------------
Title: Menzel and eclipses
Authors: Pasachoff, Jay M.
2002JHA....33..139P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book Review: Astronomy : from the earth to the universe.-
6th ed. / Thomson Learning, 2001
Authors: Pasachoff, J. M.
2002Obs...122..111P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Eclipse
Authors: Pasachoff, J.
2002eaa..bookE2017P Altcode:
An eclipse of the Sun is an OCCULTATION at which the Moon comes between
the Earth and the Sun, blocking some or all of the sunlight from
reaching an observer. Eclipses result from the fortuitous circumstance
that the angular sizes of the Sun and the Moon as seen from Earth are
the same to within about 10%, although in absolute diameter they differ
by a factor of 400....
---------------------------------------------------------
Title: Pasachoff's Points
Authors: Pasachoff, Jay M.
2002PhTea..40..196P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: A Universe from Nothing
Authors: Filippenko, Alexei V.; Pasachoff, Jay M.
2002Mercu..31b..15F Altcode:
Insights from modern physics suggest that our wondrous universe may
be the ultimate free lunch.
---------------------------------------------------------
Title: Astronomical Sacred Sites - II
Authors: Pasachoff, Jay M.
2002S&T...103b..16P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Nearest star: The surprising science of our Sun
Authors: Golub, Leon; Pasachoff, Jay M.; O'Connell, James
2002PhTea..40..127G Altcode:
No abstract at ADS
---------------------------------------------------------
Title: What Should College Students Learn?
Authors: Pasachoff, Jay M.
2002AEdRv...1a.124P Altcode:
Editor's Note: One of the key goals of the Astronomy Education Review
is to encourage open discussion about issues of interest to astronomy
educators. We begin our series of opinion pieces with a contribution
by veteran educator and author Jay Pasachoff on the subject of what
we should be teaching in the introductory college astronomy course. We
invite our readers to respond to his position and also to submit opinion
pieces on other controversial topics. (Please see the "How to Submit"
section of our site.)
---------------------------------------------------------
Title: Astronomy: From the Earth to the Universe
Authors: Pasachoff, Jay
2002afeu.book.....P Altcode:
Clear explanations, rare photographs, and authoritative commentary
makes Pasachoff's book the definitive text in introductory astronomy.
---------------------------------------------------------
Title: The Chemical Composition at the Edge of the Galaxy
Authors: Lubowich, D. A.; Pasachoff, J. M.; Millar, T. J.; Roberts,
H.; Brammer, G. B.; Henkel, C.
2001AAS...199.5804L Altcode: 2001BAAS...33Q1390L
We present initial observations to determine the chemical composition
of a molecular cloud at the edge of the Galaxy (28 kpc from the Galactic
Center). Our observations provide a unique opportunity to determine the
chemical composition and physical conditions in 10-Gyr-old less evolved
gas similar to the early Galactic disk to help understand the formation
of the Galaxy. We used the Kitt Peak 12-m telescope in June 2001 and
detected the 2-1 line of CS and the 1-0 lines of HCO<SUP>+</SUP>, HCN,
and HNC with a peak T<SUB>R<SUP>*</SUP></SUB> = 160 mK, 130 mK, 50 mK,
and 40 mK respectively. For the 1-0 lines of DNC, DCO<SUP>+</SUP>, and
N2H<SUP>+</SUP> we obtained upper limits of T<SUB>R<SUP>*</SUP></SUB>
< 6 mK, 6 mK, and 10 mK respectively. The HCN/HNC ratio indicated
that this is a cold cloud with T<SUB>kin</SUB> = 10 K - 20 K. We present
additional data from observations of SiO, SO, CH<SUB>3</SUB>OH, OCS,
H<SUB>2</SUB>CO, H<SUB>2</SUB>CS, HC<SUB>3</SUB>N, CN, C<SUB>2</SUB>H,
and H<SUB>2</SUB>S that will be conducted this fall with the Kitt
Peak 12-m and Heinrich Hertz Submillimeter Telescope telescopes. We
will test models of Galactic chemical evolution that predict that the
abundances of C, N, O will be lower than in any other Galactic cloud
and similar to dwarf irregular galaxies. We will test the possibility
that we are observing gas from an early burst of massive star formation
such as population III halo stars which would have produced some S and
O but not a significant amount of the secondary element N that is also
produced from low mass stars. We thank the Research Corporation for
providing funding for general community access to Kitt Peak 12-meter
telescope, presently operated by Steward Observatory and to the AAS
for a small research grant.
---------------------------------------------------------
Title: The Role of Research in an Astronomy or Astrophysics Major
Authors: Pasachoff, J. M.
2001AAS...19915404P Altcode: 2001BAAS...33S1534P
Undergraduates have proven capable of substantial research success in
the hundreds of projects undertaken at both Williams College and over
the past decade at its associated institutions in the Keck Northeast
Astronomy Consortium: Wellesley, Wesleyan, Middlebury, Colgate, Vassar,
Haverford, and Swarthmore. We consider the undergraduate research to
be central to our astronomy and astrophysics major programs. Research
opportunities of underclass years, usually during summers, often help
students decide to major in astronomy or astrophysics. The senior
thesis research is often a highpoint of the undergraduate educational
experience while nonthesis projects often also prove valuable for
students assessing their interests and careers. Many of the projects
have been on campus while others are at national observatories or in
other non-local research programs. Our Keck consortium has included
a student summer exchange in which 12-16 students, usually after
their sophomore or junior years, undertake research projects at
member institutions other than their own. The results are reported
at a student research symposium each fall, with approximately
35 research papers delivered; the proceedings are available. See
http://www.astro.wellesley.edu/keck/. Institutions such as those
in the consortium, with typical enrollments of 1100-2800, have been
shown to generate a higher rate of attainment of science professional
degrees than universities. Of course, many students at universities
also benefit from undergraduate research opportunities during their
undergraduate careers. Whether at colleges at universities, the personal
contact and opportunity to transfer one's abilities from book learning
to independent investigation can be invaluable in preparing students
for their post-undergraduate lives.
---------------------------------------------------------
Title: TRACE Observations of the 15 November 1999 Transit of Mercury
Authors: Schneider, G.; Pasachoff, J. M.; Golub, L.
2001DPS....33.1002S Altcode: 2001BAAS...33.1037S
We present time-resolved (38s) high-resolution (500mas) imagery of
the ingress phase of the 15 November 1999 transit of Mercury observed
with the Transition Region Coronal Explorer (TRACE) spacecraft in its
"white light" (1600 - 6000 Angstrom) channel. As part of our photometric
and astrometic analyses of this data set we examined the images in and
around the point of internal tangency for evidence of the historical
"black drop effect". After calibration (including careful removal of
image/instrumental artifacts and flat-fielding) the only radially
directed brightness anisotropes found were due to the interacting
effects the back-light solar limb-darkening, diffraction of photospheric
light around the Mercurian disk, and the instrument's Point Spread
Function. We discuss, and model, these effects as they would have
applied to earlier ground-based observations of Mercurian transits
(also including the effects of atmospheric "seeing") to explain the
historical basis for the black drop effect.
---------------------------------------------------------
Title: Nearest Star: The Surprising Science of Our Sun
Authors: Golub, Leon; Pasachoff, Jay M.; Lopez, Ramon E.
2001PhT....54k..59G Altcode:
No abstract at ADS
---------------------------------------------------------
Title: What Should College Students Learn?
Authors: Pasachoff, Jay M.
2001AEdRv...1..124P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: What should students learn?
Authors: Pasachoff, Jay M.
2001PhTea..39..381P Altcode:
It is important for students to learn about the exciting things that
are now going on in astronomy. But the application of physics research
to astronomy seems bogged down in the phases of the Moon and the cause
of the seasons.
---------------------------------------------------------
Title: Meteoritics as Visual Metaphors
Authors: Olson, R. M. J.; Pasachoff, J. M.
2001M&PSA..36R.153O Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Eclipse/SOHO Joint Observations of Solar Eclipses
Authors: Pasachoff, J. M.; Russell, K. D.; Seaton, D. B.; Babcock,
B. A.; Martin, S.
2001AGUSM..SH41B25P Altcode:
Eclipse observations extend upward from the lunar limb, and so include a
region occulted by all coronagraphs, spaceborne and mountaintop. Prior
to the 1998 total solar eclipse, we conceived a joint observation
with LASCO on SOHO to observe the solar corona with the same field
of view and same filter passband and central wavelength. We would
not only fill in the occulted region from the SOHO C1 coronagraph
but also measure the substantial scattered light on C1 as a function
of position by comparing its observations with ours. We have used a
purpose-built telescope matching SOHO's and IDL to obtain and calibrate
those observations with a 0.3 nm passband at 530.0 nm, offband from
the coronal green line. Further, with the demise of C1, we used an
improvement in our apparatus to observe on-band at 530.3 nm during the
total solar eclipse of 1999. For both eclipses, we have interposed the
EIT disk observations with our eclipse observations of the lower corona
and with LASCO C2 observations of higher coronal levels to provide a
full-field continuous image of the corona, emphasizing streamers and
other structure and tracing them from their feet on the solar disk
upward through the corona.
---------------------------------------------------------
Title: Donald H. Menzel: Scientist, Educator Builder
Authors: Pasachoff, J. M.; Gingerich, O.; Layzer, D.; Noyes, R. W.;
Parkinson, W. H.; Welther, B.
2001AGUSM..SH41B26P Altcode:
A centennial symposium in honor of Donald H. Menzel was held at the
Harvard-Smithsonian Center for Astrophysics on May 11, 2001. Menzel
was known especially for his studies of the solar chromosphere, for
his theoretical work on gaseous nebulae, and for his role in founding
the Sacramento Peak and High Altitude observatories and in bringing the
Smithsonian Astrophysical Observatory to Cambridge. Menzel received his
Ph.D. at Princeton, where he was fascinated and excited by the lectures
of Henry Norris Russell about the new theoretical astrophysics. At
Lick Observatory, Menzel investigated the solar chromosphere using
solar eclipse spectra, and published the results in a major volume
in 1931. The value for the mean molecular weight he deduced for the
lower chromosphere helped persuade Russell and others that hydrogen
was the major constituent of the solar atmosphere, as Cecilia Payne had
intimated earlier. Menzel's studies of solar eclipse spectra also led
him to propose, in a paper written with R. T. Birge, that hydrogen had
an isotope of mass 2, a suggestion that motivated Harold Urey to isolate
the isotope (deuterium) chemically. Menzel joined the Harvard faculty
in 1932. His interest in investigating the sun led him to observe
more than a dozen solar eclipses, to exploit the coronagraph, and to
found two solar observatories: at Climax, Colorado, and at Sunspot, New
Mexico. He served as Director of the Harvard College Observatory from
1952 to 1966. During this time he suggested bringing and arranged to
bring the Smithsonian Astrophysical Observatory to Harvard. Speakers at
the symposium on Menzel's life, times, and scientific legacy included
Donald Osterbrock, David DeVorkin, David Layzer, Jay Pasachoff,
Barbara Welther, Thomas Bogdan, Jack Zirker, and France Cordova. The
organizing committee was Owen Gingerich, David Layzer, Robert Noyes,
William Parkinson, Jay Pasachoff, and Barbara Welther.
---------------------------------------------------------
Title: Color Corrected
Authors: Pasachoff, Jay M.
2001S&T...101e..18P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: On teaching introductory astronomy
Authors: Pasachoff, Jay M.
2001PhTea..39..198P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Pro-Am Solar-Eclipse Conference, A
Authors: Pasachoff, Jay M.
2001S&T...101b..45P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Early Eclipse Science
Authors: Pasachoff, Jay M.
2001S&T...101b..46P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book Review: Shoemaker by Levy : the man who made an impact /
Princeton University Press, Princeton, New Jersey, 303 pp., 2000,
ISBN 0-691-00225-8.
Authors: Pasachoff, Jay M.
2001Ast....29b.100P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Solar-Eclipse Science: Still Going Strong
Authors: Pasachoff, Jay M.
2001S&T...101b..40P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Moon-Struck: Artists Rediscover Nature And Observe
Authors: Pasachoff, Jay M.; Olson, Roberta J. M.
2001EM&P...85..303P Altcode: 1999EM&P...85..303P
We discuss rare early depictions of the Moon by artists who actually
observed Earth's nearest neighbor rather than relying on stylized
formulas. The earliest, from the 14th and 15th centuries, reveal that
revolutionary advances in both pre-telescopic astronomy and naturalistic
painting could go hand-in-hand. This link suggests that when painters
observed the world, their definition of world could also include the
heavens and the Moon. Many of the artists we discuss - e.g., Pietro
Lorenzetti, Giotto, and Jan Van Eyck - actually studied the Moon,
incorporating their studies into several works. We also consider the
star map on the dome over the altar in the Old Sacristy of San Lorenzo,
Florence (c. 1442), whose likely advisor was Toscanelli. In addition, we
examine representations by artists who painted for Popes Julius II and
Leo X - Raphael and Sebastiano del Piombo, both of whom were influenced
by individuals at the papal court, such as the astronomer, painter,
and cartographer Johann (Giovanni) Ruysch and Leonardo da Vinci. We
also discuss Leonardo's pre-telescopic notes and lunar drawings as they
impacted on art and science in Florence, where Galileo would study
perspective and chiaroscuro. Galileo's representations of the Moon
(engraved in his Sidereus Nuncius, 1610) are noted, together with those
by Harriot and Galileo's friend, the painter Cigoli. During the 17th
century, the Moon's features were telescopically mapped by astronomers
with repercussions in art, e.g., paintings by Donati Creti and Raimondo
Manzini as well as Adam Elsheimer. Ending with a consideration of the
19th-century artists/astronomers John Russell and John Brett and early
lunar photography, we demonstrate that artistic and scientific visual
acuity belonged to the burgeoning empiricism of the 14th, 15th, and
16th centuries that eventually yielded modern observational astronomy.
---------------------------------------------------------
Title: The Cosmos: Astronomy in the New Millennium
Authors: Pasachoff, Jay; Filippenko, Alex
2001canm.book.....P Altcode:
Pasachoff/Filippenko represent a team that brings together experience in
writing, research, and teaching. This book provides a brief, up-to-date,
and beautifully illustrated overview of astronomy. Pasachoff/Filippenko
are each very experienced in teaching elementary astronomy to
their student and bring that experience to bear in this text. Visit
www.harcourtcollege.com/astro/cosmos for further information.
---------------------------------------------------------
Title: A Proper Wave to Maxwell
Authors: Pasachoff, Jay M.
2001S&T...101a..14P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Nearest star : the surprising science of our sun
Authors: Golub, Leon; Pasachoff, Jay M.
2001nsss.book.....G Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Public education in developing countries on the occasions
of eclipses
Authors: Pasachoff, Jay M.
2001IAUGA..24..101P Altcode: 2000IAUSS..24E..38P
Total solar eclipses will cross southern Africa on June 21, 2001,
and on December 4, 2002. Most of Africa will see partial phases. The
total phase of the 2001 eclipse will be visible from parts of Angola,
Zambia, Zimbabwe, Mozambique and Madagascar. The total phase of the
2002 eclipse will be visible from parts of Angola, Botswana, Zimbabwe,
South Africa and Mozambique. Public education must be undertaken to tell
the people how to look at the eclipse safely. We can take advantage of
having the attention of the people and of news media to teach about
not only eclipses but also the rest of astronomy. I am Chair of a
"Public Education at Eclipses" subcommission of IAU Commission 46 on
the Teaching of Astronomy, and we are able to advise educators and
others about materials, procedures and information releases.
---------------------------------------------------------
Title: Deuterium Near and Far in the Galaxy
Authors: Lubowich, D. A.; Pasachoff, Jay M.; Ostenson, Jason A.
2001coev.conf...63L Altcode:
We report on our program to determine the deuterium abundance
distribution in the Milky Way. We have reported D/H =
1.7×10<SUP>-6</SUP> in a molecular cloud 10 pc from the Galactic
Center, from which we infer recent continuous infall of pregalactic
primordial gas. We have searched for the Balmer Da lines with high S/N
= 300 - 1000 observations of a halo star (HD 140283), slowly rotating
B stars (ι Her and γ Peg), H II regions (Orion Nebula and M17),
and the planetary nebula NGC 7027.
---------------------------------------------------------
Title: The Prediction and Observation of the 1997 July 18 Stellar
Occultation by Triton: More Evidence for Distortion and Increasing
Pressure in Triton's Atmosphere
Authors: Elliot, J. L.; Person, M. J.; McDonald, S. W.; Buie, M. W.;
Dunham, E. W.; Millis, R. L.; Nye, R. A.; Olkin, C. B.; Wasserman,
L. H.; Young, L. A.; Hubbard, W. B.; Hill, R.; Reitsema, H. J.;
Pasachoff, J. M.; McConnochie, T. H.; Babcock, B. A.; Stone, R. C.;
Francis, P.
2000Icar..148..347E Altcode:
A variety of CCD astrometric data was used to predict the location of
the path for the occultation of the star we have denoted "Tr176" by
Triton, which occurred on 1997 July 18, and was visible from locations
in northern Australia and southern North America. A network of fixed
and portable telescopes equipped with high-speed photometric equipment
was set up to observe the event, with the following observational
goals: (i) mapping the central flash (to establish the global
shape of Triton's atmosphere at about 20-km altitude by modeling
the detailed shape of the central flash), (ii) obtaining one or more
light curves of high signal-to-noise ratio from a large telescope (to
accurately determine the thermal structure of Triton's atmosphere),
and (iii) obtaining light curves distributed across Triton's disk (to
probe the thermal structure of Triton's atmosphere above different
areas and to establish the shape of the atmosphereat about 100-km
altitude by modeling the half-light surface). Although the large,
fixed telescopes proved to be outside of the occultation shadow and
observations with some of the portable telescopes were foiled by clouds,
light curves were successfully recorded from Brownsville, Texas, and
Chillagoe, Queensland. These were combined with data from another
group to determine the radius and shape of the half-light surface
in Triton's atmosphere and the equivalent-isothermal temperatures at
the sub-occultation latitudes on Triton. A circular solution for the
half-light surface (projected into Triton's shadow) yielded a radius of
1439±10 km. However, the data are indicative of a global shape more
complex than a sphere. Such a figure is most likely caused by strong
winds. Light-curve models corresponding to the best fitting circular
and elliptical atmospheres were fit to the data. The mean pressure
at 1400-km radius (48-km altitude) derived from all of the data was
2.23±0.28 μbar for the circular model and 2.45±0.32 μbar for the
elliptical model. These values suggest a global pressure increase at
this level since a previous Triton occultation in 1995 August. The mean
equivalent-isothermal temperature at 1400 km was 43.6±3.7 K for the
circular model and 42.0±3.6 K for the elliptical model. Within their
(sometimes large) uncertainties, the equivalent-isothermal temperatures
agree for all Triton latitudes probed.
---------------------------------------------------------
Title: Further Evidence for Increasing Pressure and a Non-spherical
Shape in Triton's Atmosphere
Authors: Person, M. J.; Elliot, J. L.; McDonald, S. W.; Buie, M. W.;
Dunham, E. W.; Millis, R. L.; Nye, R. A.; Olkin, C. B.; Wasserman,
L. H.; Young, L. A.; Hubbard, W. B.; Hill, R.; Reitsema, H. J.;
Pasachoff, J. M.; Babcock, B. A.; McConnochie, T. M.; Stone, R. C.
2000DPS....32.4502P Altcode: 2000BAAS...32.1082P
An occultation by Triton of a star denoted as Tr176 by McDonald &
Elliot (AJ 109, 1352), was observed on 1997 July 18 from various
locations in Australia and North America. After an extensive prediction
effort, two complete chords of the occultation were recorded by our
PCCD portable data systems. These chords were combined with three
others recorded by another group (Sicardy et al., BAAS 30, 1107)
to provide an overall geometric solution for Triton's atmosphere at
the occultation pressure. A simple circular fit to these five chords
yielded a half-light radius of 1439 +/- 10 km, however least squares
fitting revealed a significant deviation from the simple circular
projection of a spherical atmosphere. The best fitting ellipse (a first
order deviation from the circular solution) yielded a mean radius
of 1440 +/- 6 km and an ellipticity of 0.040 +/- 0.003. To further
characterize the non-spherical solutions to the geometric fits,
methods were developed to analyze the data assuming both circular
and elliptical profiles. Circular and elliptically focused light
curve models corresponding to the best fitting circular and elliptical
geometric solutions were fit to the data. Using these light curve fits,
the mean pressure at the 1400 km radius (48 km altitude) derived from
all the data was 2.23 +/- 0.28 microbar for the circular model and 2.45
+/- 0.32 microbar for the elliptical model. These pressures agree with
those for the Tr180 occultation (which occurred a few months later),
so these results are consistent with the conclusions of Elliot et
al. (Icarus 143, 425) that Triton's surface pressure has increased from
14.0 microbar at the time of the Voyager encounter to 19.0 microbar in
1997. The mean equivalent-isothermal temperature at 1400 km was 43.6
+/- 3.7 K for the circular model and 42.0 +/- 3.6 K for the elliptical
model. Within their calculated errors, the equivalent-isothermal
temperatures were the same for all Triton latitudes probed.
---------------------------------------------------------
Title: A search at two eclipses for short-period waves that heat
the corona
Authors: Pasachoff, Jay M.; Babcock, Bryce A.; Russell, Kevin D.;
McConnochie, Timothy H.; Diaz, J. Sebastian
2000SoPh..195..281P Altcode:
As part of a study of the cause of solar coronal heating, we searched
for high-frequency (∼1 Hz) intensity oscillations in coronal loops in
the [Fe xiv] coronal green line. We summarize results from observations
made at the 3 November 1994, total solar eclipse from the International
Astronomical Union site in Putre, Chile, through partly cloudy skies,
and at the 26 February 1998 total solar eclipse from Nord, Aruba,
through clear skies. We discuss the image reduction and analysis of two
simultaneous series of coronal CCD images digitized at 10 Hz for a total
time of 160 s in Chile. One series of images was taken through a filter
isolating the 5303 Å[Fe xiv] coronal green line and the other through
a 100 Å filter in the nearby K-corona continuum. We then discuss the
modifications made for the 1998 eclipse, and the image reduction and
analysis for those image sequences. After standard calibrations and
image alignment of both data sets, we use Fourier analysis to search in
the [Fe xiv] channel for intensity oscillations in loops at the base
of the corona. Such oscillations in the 1-Hz range are predicted as
a result of density fluctuations from the resonant absorption of MHD
waves. The dissipation of a significant amount of mechanical energy
from the photosphere into the corona through this mechanism could
provide sufficient energy to heat the corona. At neither eclipse do we
find evidence for oscillations in the [Fe xiv] green line at a level
greater than 2% of coronal intensity.
---------------------------------------------------------
Title: Deuterium in the Galactic Centre as a result of recent infall
of low-metallicity gas
Authors: Lubowich, D. A.; Pasachoff, Jay M.; Balonek, Thomas J.;
Millar, T. J.; Tremonti, Christy; Roberts, Helen; Galloway, Robert P.
2000Natur.405.1025L Altcode:
The Galactic Centre is the most active and heavily processed region
of the Milky Way, so it can be used as a stringent test for the
abundance of deuterium (a sensitive indicator of conditions in the
first 1,000 seconds in the life of the Universe). As deuterium is
destroyed in stellar interiors, chemical evolution models predict
that its Galactic Centre abundance relative to hydrogen is D/H =
5 × 10<SUP>-12</SUP>, unless there is a continuous source of
deuterium from relatively primordial (low-metallicity) gas. Here
we report the detection of deuterium (in the molecule DCN) in a
molecular cloud only 10 parsecs from the Galactic Centre. Our data,
when combined with a model of molecular abundances, indicate that
D/H = (1.7 +/- 0.3) × 10<SUP>-6</SUP>, five orders of magnitude
larger than the predictions of evolutionary models with no continuous
source of deuterium. The most probable explanation is recent infall of
relatively unprocessed metal-poor gas into the Galactic Centre (at the
rate inferred by Wakker). Our measured D/H is nine times less than the
local interstellar value, and the lowest D/H observed in the Galaxy. We
conclude that the observed Galactic Centre deuterium is cosmological,
with an abundance reduced by stellar processing and mixing, and that
there is no significant Galactic source of deuterium.
---------------------------------------------------------
Title: Eclipse Observations of Coronal Structure, Polarization,
and Oscillations from 11 August 1999
Authors: Pasachoff, J. M.; Babcock, B. A.; Russell, K. D.; May, S. K.
2000AAS...196.4904P Altcode: 2000BAAS...32..750P
We report on CCD observations of the corona from Ramnicu Valcea,
Romania, during the total solar eclipse of 11 August 1999. One
experiment searched for oscillations in the 530.3-nm coronal green line
at about 1 Hz by digitizing at 10 Hz, as a determination of the coronal
oscillation spectrum to test models of magnetohydrodynamic heating. The
optical system was improved in several ways since the 1998 expedition,
as was monitoring of the filter. The series of images was aligned and
Fourier transforms were examined for individual pixels and groups of
pixels. No oscillations were clearly detected above the 1% level, though
statistical analysis continues at this writing. A second experiment took
a series of 36 images through one filter wheel that contained three
filters near 400 nm and a second filter wheel containing polarizers
at three angles plus a parfocal clear filter. The results include a
polarization map of a quadrant of the sun and an attempt to map the
coronal temperature. The temperature map uses techniques suggested by
Cram (1976) through a determination of the extent to which scattering
off high-temperature electrons wash out the photospheric Fraunhofer
lines. Low-pass filtering of our resultant images show detail in the
form of coronal loops but do not show much non-radial structure in
the temperature variations. We also compare composite photographic
observations with EIT images from eclipse day. The expedition was
supported by NSF grant ATM-9812408, National Geographic Society grant
6449-99, the Keck Northeast Astronomy Consortium, and NASA SOHO/EIT
guest-investigator grant NRA-98-03-SEC-051.
---------------------------------------------------------
Title: SECIS: The Solar Eclipse Coronal Eclipse Imaging System
Authors: Phillips, K. J. H.; Read, P. D.; Gallagher, P. T.; Keenan,
F. P.; Rudawy, P.; Rompolt, B.; Berlicki, A.; Buczylko, A.; Diego,
F.; Barnsley, R.; Smartt, R. N.; Pasachoff, J. M.; Babcock, B. A.
2000SoPh..193..259P Altcode:
The Solar Eclipse Coronal Imaging System (SECIS) is an instrument
designed to search for short-period modulations in the solar corona
seen either during a total eclipse or with a coronagraph. The CCD
cameras used in SECIS have the capability of imaging the corona at a
rate of up to 70 frames a second, with the intensities in each pixel
digitised in 12-bit levels. The data are captured and stored on a
modified PC. With suitable optics it is thus possible to search for
fast changes or short-period wave motions in the corona that will
have important implications for the coronal heating mechanism. The
equipment has been successfully tested using the Evans Solar Facility
coronagraph at National Solar Observatory/Sacramento Peak and during
the 11 August 1999 eclipse at a site in north-eastern Bulgaria. The
instrument is described and preliminary results are outlined.
---------------------------------------------------------
Title: Wiliams College, Hopkins Observatory, Williamstown,
Massachusetts 01267. Report for the period 1 Jul 1998 - 1 Sep 1999.
Authors: Pasachoff, J. M.; Kwitter, K. B.
2000BAAS...32..619P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The Deuterium Abundance In The Galactic Center 50 km/s
Molecular Cloud: Evidence For A Cosmological Origin Of D
Authors: Lubowich, D. A.; Pasachoff, J. M.; Galloway, R. P.; Balonek,
T. J.; Tremonti, C.; Millar, T.; Roberts, H.
2000IAUS..198..167L Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Commission 46: Teaching of Astronomy: (Enseignement de
L'astronomie)
Authors: Fierro, Julieta; Isobe, Syuzo; Jones, B.; Batten, A.;
Arellano, A.; Gervaldi, M.; Guinan, E.; Tush, W.; Hoff, D.; Martinez,
P.; McNally, D.; Norton, A.; Narlikar, J.; Pasachoff, J.; Percy, J.;
Wentzel, D.
2000IAUTA..24..423F Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The Williams College expedition to Râmnicu Vâlcea
Authors: Pasachoff, Jay M.
2000ASIC..558...23P Altcode: 2000asre.conf...23P
The Williams College expedition to Râmnicu Vâlcea, Romania, made
observations of the solar corona (a) to compare with the Extreme
ultraviolet Imaging Telescope (EIT) on the Solar and Heliospheric
Observatory; (b) to search for the source of coronal heating through a
study of the oscillatory power spectrum of coronal loops in an emission
line typical of high temperature; (c) mapped the coronal temperature
using ultraviolet continuum observations; (d) made videos and still
photographs of coronal motions and details; and (e) collaborated with
the scientists at the Astronomical Institute in Bucharest.
---------------------------------------------------------
Title: Fire in the Sky
Authors: Olson, Roberta J. M.; Pasachoff, Jay M.
1999fisk.book.....O Altcode:
Fire in the Sky collects many representations of comets and meteors in
Britain during the eighteen and nineteenth century when a large number
of works inspired by these celestial objects were produced. Over 100
photographs--and two sections of luscious color plates--beautifully
portray the inspired output of some of the world's most talented
artists, fully capturing the phenomenon that obsessed not only
a nation but an era as well. Olson and Pasachoff reveal the many
different ways that comets and meteors have appeared in paintings and
literature and link these works to the achievements of British science
in the wake of Newton and Halley. They also examine the different
symbolism that writers and artists have attached to these spectacular
objects. Throughout, Fire in the Sky conveys how the development of
new technologies, and the burgeoning interest of the general public
in science and art, dovetailed with an interest in nature and a
strong literary tradition of comet and meteor symbolism. Beautifully
illustrated and packed with engaging stories, this book will delight
anyone with an interest in the art and astronomy of comets.
---------------------------------------------------------
Title: Comets, meteors, and eclipses: art and science in early
renaissance Italy (Invited).
Authors: Olson, R. J. M.; Pasachoff, J. M.
1999BAAS...31.1080O Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Comets, Meteors, and Eclipses: Art and Science in Early
Renaissance Italy (Invited)
Authors: Olson, R. J. M.; Pasachoff, J. M.
1999DPS....31.0701O Altcode:
We discuss several topics relating artists and their works with
actual astronomical events in early Renaissance Italy to reveal
the revolutionary advances made in both astronomy and naturalistic
painting. Padua, where Galileo would eventually hold a chair at
the University, was already by the fourteenth century (trecento)
a renowned center for mathematics and nascent astronomy (which was
separating from astrology). It is no wonder that when Enrico Scrovegni
commissioned the famous Florentine artist Giotto di Bondone to decorate
his lavish family chapel (c. 1303) that in the scene of the Adoration
of the Magi Giotto painted a flaming comet in lieu of the traditional
Star of Bethlehem. Moreover, he painted an historical apparition he
recently had observed with a great understanding of its scientific
structure: Halley's Comet of 1301 (since Olson's first publication
of this idea in Scientific American we have expanded the argument
in several articles and talks). While we do not know the identity
of the artist's theological advisor, we discuss the possibility
that Pietro d'Abano, the Paduan medical doctor and “astronomer"
who wrote on comets, might have been influential. We also compare
Giotto's blazing comet with two others painted by the artist's
shop in San Francesco at Assisi (before 1316) and account for the
differences. In addition, we tackle the question how Giotto's pupil,
Taddeo Gaddi, who is documented as having been partially blinded by
lengthy unprotected observation of the partial phase of an annular
solar eclipse, reflects his observations in his frescoes in Santa Croce,
Florence (1328-30). Giotto also influenced the Sienese painter Pietro
Lorenzetti, two of whose Passion cycle frescoes at Assisi (1316-20),
contain dazzling meteor showers that hold important symbolic meanings
in the cyle's argument but more importantly reveal that the artist
observed astronomical phenomena, such as the “radiant" effect, which
was first recorded by Alexander von Humboldt in 1799 and only accepted
in the nineteenth century. Lorenzetti also painted sporadic, independent
meteors, which do not emanate from the radiant, demonstrating that he
observed this phenomenon as well. (It is significant that these artists
knew the differences between comets and meteors, facts which were not
absolutely established until the eighteenth century.) We demonstrate
that artistic and scientific visual acuity were part of the burgeoning
empiricism of the fourteenth century that eventually yielded modern
observational astronomy. Our joint work has been supported in part by
the National Endowment for the Humanities and the Getty Grant Program.
---------------------------------------------------------
Title: Halley and his maps of the Total Eclipses of 1715 and 1724
Authors: Pasachoff, Jay M.
1999JAHH....2...39P Altcode:
Edmond Halley was perhaps the first, in 1715, to draw the path of an
eclipse as seen from above, looking down at the Earth's surface. I
compare four eclipse-path maps drawn for Halley: one before the 1715
eclipse, one with a corrected path after the eclipse and including
the predicted path for the 1724 eclipse, a reissue of that map
just before the latter eclipse, and a different map for that latter
eclipse. These maps are in the collection of the Houghton Library of
Harvard University. For comparison, I provide a current map of the
1999 total solar-eclipse path, which is similar to that of 1724.
---------------------------------------------------------
Title: Halley's Maps and Descriptions of the 1715 Total Solar Eclipse
Authors: Pasachoff, J. M.
1999AAS...194.0108P Altcode: 1999BAAS...31..824P
Edmond Halley was perhaps the first to present eclipse maps to the
public in their common current form: looking down on the Earth's surface
from above. For the 1715 total solar eclipse that crossed England,
he prepared broadsheets showing the eclipse path and describing
what would be expected. After the eclipse, he corrected the eclipse
path, and added the path and description of the 1724 total solar
eclipse. His separate path for the latter resembles the path of the
August 11, 1999, eclipse as drawn by Fred Espenak in his NASA Reference
Publication. All four of the Halley maps are in the Houghton Library,
Harvard University. Halley described observations of the 1715 eclipse
in the Philosophical Transactions of the Royal Society, including
both his own observations and those of other observatories. The need
for advising the public about forthcoming eclipses and how to observe
them safely continues from Halley's time down to this day.
---------------------------------------------------------
Title: Halley and his maps of the total eclipses of 1715 and 1724
Authors: Pasachoff, Jay
1999A&G....40b..18P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Halley et ses cartes des éclipses totales de 1715 et 1724.
Authors: Pasachoff, J. M.
1999C&T...115...51P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The Solar Corona
Authors: Golub, Leon; Pasachoff, Jay M.; Smartt, Raymond N.
1999AmJPh..67..263G Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Williams College, Hopkins Observatory, Williamstown,
Massachusetts 01267. Report for the period 1 Jul 1997 - 30 Jun 1998.
Authors: Pasachoff, J. M.; Kwitter, K. B.
1999BAAS...31..650P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Linking a Textbook with the World Wide Web
Authors: Pasachoff, J. M.
1998AAS...193.7801P Altcode: 1998BAAS...30.1371P
The pace of astronomy is such that a printed textbook is out of date
by the time it appears, though a cooperative publisher can allow a
book to be six months or so more current than others with the same
copyright date. I have endeavored to allow faculty and students to
bring their textbook up to date on the day of each lecture or each
reading assignment by providing a Web site linked chapter-by-chapter
to my text Astronomy: From the Earth to the Universe, 5th edition,
1998. The URL http://www.williams.edu/Astronomy/jay contains updates,
new discussions, errata, and links to other sites. The site also allows
feedback and links to both author and publisher.
---------------------------------------------------------
Title: Book Review: The solar corona / Cambridge U Press, 1997
Authors: Golub, L.; Pasachoff, J. M.
1998SoPh..183..227G Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Weighty planets
Authors: Pasachoff, Jay M.
1998PhTea..36..324P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The FAQs of astronomy
Authors: Pasachoff, Jay M.
1998Natur.394..438P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Global warming on Triton
Authors: Elliot, J. L.; Hammel, H. B.; Wasserman, L. H.; Franz, O. G.;
McDonald, S. W.; Person, M. J.; Olkin, C. B.; Dunham, E. W.; Spencer,
J. R.; Stansberry, J. A.; Buie, M. W.; Pasachoff, J. M.; Babcock,
B. A.; McConnochie, T. H.
1998Natur.393..765E Altcode:
Triton, Neptune's largest moon, has been predicted to undergo
significant seasonal changes that would reveal themselves as changes
in its mean frost temperature. But whether this temperature should at
the present time be increasing, decreasing or constant depends on a
number of parameters (such as the thermal properties of the surface, and
frost migration patterns) that are unknown. Here we report observations
of a recent stellar occultation by Triton which, when combined with
earlier results, show that Triton has undergone a period of global
warming since 1989. Our most conservative estimates of the rate of
temperature and surface-pressure increase during this period imply
that the atmosphere is doubling in bulk every 10 years-significantly
faster than predicted by any published frost model for Triton,. Our
result suggests that permanent polar caps on Triton play a dominant
role in regulating seasonal atmospheric changes. Similar processes
should also be active on Pluto.
---------------------------------------------------------
Title: Williams College's Hopkins Observatory: the oldest extant
observatory in the United States
Authors: Pasachoff, Jay M.
1998JAHH....1...61P Altcode:
The Hopkins Observatory, built at Williams College in 1836-1838, is the
oldest astronomical observatory extant in the United States. Founded
by Professor Albert Hopkins and built together with his students, it
still contains the oldest known Alvan Clark telescope. Some of its
historic instruments are mounted in its wings, known as the Mehlin
Museum of Astronomy, and its central internal domed-ceiling room is
the Milham Planetarium.
---------------------------------------------------------
Title: Fire in the Sky
Authors: Olson, Roberta J. M.; Pasachoff, Jay M.
1998fisk.book.....O Altcode:
Introduction; 1. Prelude: the beginning of telescopic astronomy and
the background of British astronomy and artistic traditions; 2. The
heavens on fire: the eighteenth century; 3. The comet-crazed century
opens; 4. The triumph of realism; 5. Donati's comet, the watershed;
6. The origin of comet (and meteor) photography; 7. The triumph of the
imagination; 8. Comets and the new century; Epilogue: comets and the
new millennium; Appendices; List of illustrations; Bibliography; Index.
---------------------------------------------------------
Title: Fire in the Sky: Comets and Meteors, the Decisive Centuries,
in British Art and Science
Authors: Olson, R. J. M.; Pasachoff, J. M.
1998fscm.book.....O Altcode:
Comets and meteors are spectacular and awe-inspiring natural phenomena,
which are among nature's most compelling icons. Since the beginning of
recorded time, they have mesmerized people, not least among them artists
and astronomers. Britain during the eighteenth and nineteenth centuries
produced a larger number and greater variety of representations of
comets and meteors than any other country. The development of new
technologies, and the burgeoning interest of the general public in
science and art, dovetailed with the inherent British interest in nature
and a strong literary tradition of comet and meteor symbolism. This
beautifully illustrated book examines the link between these works
and the achievements of British science in the wake of Newton and
Halley. This book will be stimulating to anyone interested in the art
or astronomy of comets.
---------------------------------------------------------
Title: Use of the World Wide Web in Astronomy Teaching
Authors: Pasachoff, J. M.
1998ntat.coll...68P Altcode: 1998IAUCo.162...68P
No abstract at ADS
---------------------------------------------------------
Title: Astronomy: From the Earth to the Universe
Authors: Pasachoff, J. M.
1998afeu.book.....P Altcode:
The latest edition of a wonderful general-astronomy book meant for
the introductory survey course in American universities. Highly
illustrated. Covers the wide range of astronomy.
---------------------------------------------------------
Title: A Field Guide to the Stars and Planets
Authors: Pasachoff, J. M.; Menzel, D. H.
1998fgsp.book.....P Altcode:
The standard field guide for amateur observing; also usable for
reference at professional telescopes. Many useful tables.
---------------------------------------------------------
Title: Mars Pathfinder slide set
Authors: Pasachoff, Jay M.; Britt, Daniel
1998mpss.book.....P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Solar Eclipses and Public Education
Authors: Pasachoff, J. M.
1998ntat.coll..202P Altcode: 1998IAUCo.162..202P
No abstract at ADS
---------------------------------------------------------
Title: Total solar eclipse to sweep across Americas
Authors: Pasachoff, Jay M.
1997PhTea..35Q.515P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The Solar Corona
Authors: Golub, Leon; Pasachoff, Jay M.
1997soco.book.....G Altcode:
Observations from the ground and space have advanced our knowledge
of the solar corona dramatically over the past three decades. This
timely volume presents a lucid and synthesized review of the latest
observations of the solar corona and discusses how these observations
have advanced and shaped our understanding of coronal physics. In
the process, the authors introduce a wide variety of exciting
physics, including dynamo theory and radiative transfer. They also
demonstrate how the transient effects of the solar cycle effect "space
weather." This book provides a much-needed introduction to coronal
physics for advanced students and researchers.
---------------------------------------------------------
Title: Hubble `worth the price'
Authors: Pasachoff, Jay M.
1997Natur.387..754P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Pitfalls in the Science Standards
Authors: Pasachoff, Jay M.
1997APS..APR..M203P Altcode:
The National Science Standards ask for "relevance" and use a very
limited set of topics. The "less is more" approach leaves out many
topics that practicing physicists and teachers believe are essential
for equipping students to see the roles of science in the modern
world. The Standards' request for "relevance" may also not match
the inspirational topics of today's physics and astronomy. If these
problems are not considered as the Standards become incorporated
in curricula, a substantial fall in student interest in physics and
astronomy could result.
---------------------------------------------------------
Title: Panel and Audience Discussion
Authors: Quinn, Helen; Alberts, Bruce; Stith, James H.; Pasachoff,
Jay M.; Orpwood, Graham
1997APS..APR..M205Q Altcode:
Participating Panelists: Bruce Alberts, National Academy of Sciences
James H. Stith, Department of Physics, Ohio State University Jay
M. Pasachoff, Astronomy Department, Williams College Graham Orpwood,
Faculty of Education, York University
---------------------------------------------------------
Title: Solar eclipses as a vehicle for international astronomy
education.
Authors: Pasachoff, J. M.
1997ASIC..494..249P Altcode: 1997topr.conf..249P
The public's attention is drawn to astronomy whenever solar eclipse -
partial, annular, or total - is visible, and we must take advantage
of the opportunity to teach about the nature of science, the ability
of astronomers to predict and analyze distant bodies and events, and
the value of scientific research. We must also instruct people how to
watch the partial and annular phases safely and that the total phase
is not harmful.
---------------------------------------------------------
Title: Coronal heating experiments of the Williams College Group at
Mukandgarh Fort, Rajasthan.
Authors: Pasachoff, J. M.; Babcock, B. A.; Diaz, S.; Reardon, K. P.;
Kutner, E. R.
1997KodOB..13...75P Altcode:
The authors report on the Williams College expedition to Mukandgarh
Fort, Rajasthan, for the total solar eclipse of 24 October 1995. The
main experiments were a search for 1 Hz oscillations in coronal loops
as an indication of magnetohydrodynamic theories of coronal heating
and a mapping of the coronal temperature through comparison of images
at specific ultraviolet wavelengths, measuring the difference between
the photospheric and coronal continuum. The authors also obtained a
variety of coronal images.
---------------------------------------------------------
Title: Eclipse observations relevant to the coronal heating problem.
Authors: Pasachoff, J. M.
1997ASIC..494..181P Altcode: 1997topr.conf..181P
The author is studying the coronal oscillation spectrum and its
implications on the heating of the solar corona through the reduction
of his data from observations of the total solar eclipse of 24 October
1995 and with further theoretical and observational investigations. The
observations provide tests of proposed mechanisms to explain the
heating of the solar corona via weakly compressive magnetohydrodynamic
waves. The author is also mapping the electron temperature of the corona
through study of the broadening by electron scattering of ultraviolet
Fraunhofer lines.
---------------------------------------------------------
Title: Cosmic Questions: Galactic Halos, Cold Dark Matter, and the
End of Time
Authors: Morris, Richard; Kutner, Eric R.; Pasachoff, Jay M.
1996AmJPh..64.1437M Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The Earliest Comet Photographs: Usherwood, Bond, and Donati
1858
Authors: Pasachoff, Jay M.; Olson, Roberta J. M.; Hazen, Martha L.
1996JHA....27..129P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The Universe Wide Web
Authors: Pasachoff, Jay M.
1996PhTea..34..134P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Textbooks and Electronic Media
Authors: Pasachoff, Jay M.
1996ASPC...89...66P Altcode: 1996aecd.conf...66P
No abstract at ADS
---------------------------------------------------------
Title: Study of the High-Frequency Coronal-Loop Oscillation Spectrum
at the 1994 Total Solar Eclipse
Authors: Pasachoff, J. M.; Babcock, B.; Diaz, J. S.; Reardon, K.;
Nichols-Kiley, R.
1995AAS...18710106P Altcode: 1995BAAS...27.1427P
We summarize results from observations made at the November 3, 1994,
total solar eclipse from the International Astronomical Union site
in Putre, Chile, through partly cloudy skies. We discuss the image
reduction and analysis of two simultaneous series of coronal images with
a cadence of 10 frames per second for a total time of 160 seconds. One
series of images was taken through a filter isolating the 530.3 nm
[Fe XIV] coronal green line and the other through a 10 nm filter in
the nearby K-corona continuum. After standard calibrations and image
alignment, we use Fourier analysis to search in the [Fe XIV] channel
for high-frequency ( 1 Hz) intensity oscillations in loops at the base
of the corona. Such oscillations are predicted as a result of density
fluctuations from the resonant absorption of high-frequency Alfven
waves. The dissipation of a significant amount of mechanical energy from
the photosphere into the corona through this mechanism could provide
sufficient energy to heat the corona. The observations were supported by
NSF ATM-9005194 and Education Division DUE-9351279 grants; the National
Geographic Society through their Committee on Research and Explorations
(grant: 5190-94), and the Keck Northeastern Astronomy Consortium.
---------------------------------------------------------
Title: The Earliest Comet Photographs: Usherwood and Bond for
Donati 1858
Authors: Pasachoff, J. M.; Olson, R. J. M.
1995AAS...187.3501P Altcode: 1995BAAS...27.1331P
The first known photographs of a comet were taken in 1858. The
earliest astronomical telescopic photographs, daguerreotypes from
1850-51, had been made only when the violet focus of telescopes was
found. Tracking remained a problem preventing astronomical objects from
being photographed. When the Harvard refractor's tracking was improved
in 1858, it was used by the Bonds and colleagues to photograph Comet
Donati on a collodion plate. The plate remains in the archives of the
Harvard College Observatory, though the image shows only very faintly
and no tail can be seen. Bond was scooped the previous night by the
commercial English photographer W. Usherwood, who used a portrait camera
at a much lower focal ratio to capture the comet's tail. The plate was
seen and evaluated by W.C. Bond. No further comet photography took place
until 1881, when P.J.C. Janssen and J.W. Draper took the first generally
recognized photographs of a comet, followed by D. Gill's photographs
of the Great September comet of 1882. This work was sponsored by two
Senior Research Grants from the Getty Grant Program.
---------------------------------------------------------
Title: Showing Women in Astronomy
Authors: Pasachoff, Jay M.
1995AmJPh..63..873P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book Review: The farthest things in the universe / Cambridge
U Press, 1994
Authors: Pasachoff, J. M.; Spinrad, H.; Osmer, P.; Cheng, E.; Jones, T.
1995Obs...115..137P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book-Review - Astronomy - from the Earth to the Universe - ED.4
Authors: Pasachoff, J. M.; Mizon, B.
1995JBAA..105..185P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book-Review - the Farthest Things in the Universe
Authors: Pasachoff, J. M.; Spinrad, H.; Osmer, P.; Cheng, E.; Glass,
I. S.
1995MNSSA..54...46P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Comets and meteors in 18th and 19th century British art
and science.
Authors: Pasachoff, J. M.; Olson, R. J. M.
1995PhyEd..30..156P Altcode:
Comparing paintings, drawings and prints of comets and meteors in
British works of art and scientific records of the 18th and 19th
centuries brings us to a study of the relationship between science and
art. Representations were sometimes naturalistic, sometimes symbolic
and sometimes satirical. The British interest in images of comets and
meteors, which were not clearly distinguished from each other during
much of the period, coincided with the era that celebrated the progress
in science exemplified by the discoveries of Newton and Halley. At
the end of the period in question, the invention of photography,
and its subsequent improvement to the point where faint objects like
comets could be recorded, altered the dynamics. The changes in both
intellectual climate and technology resulted in an increasing separation
between the arts and the sciences.
---------------------------------------------------------
Title: Books-Received - Astronomy - from the Earth to the Universe
- ED.4
Authors: Pasachoff, J. M.
1995Sci...268..136P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Books-Received - the Farthest Things in the Universe
Authors: Pasachoff, J. M.
1995Sci...268..315P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Coronal Heating Studies at the 1994 Total Eclipse
Authors: Pasachoff, J. M.; Babcock, B.; Reardon, K.
1995pist.conf...18P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The Farthest Things in the Universe
Authors: Pasachoff, Jay M.; Spinrad, Hyron; Osmer, Patrick; Cheng,
Edward S.
1995ftu..book.....P Altcode:
The quest for the farthest objects in the Universe remains one of
the most challenging areas of modern astronomical research. Peering
deeper and deeper into space reveals the most distant and powerful
objects known and so unveils the embryonic epochs of the Universe
not long after its birth in the Big Bang. Four world experts--chosen
for their ability to communicate research astronomy at a popular
level--each contributes a chapter to this lucid survey. They address
the fundamental issues of scale in the Universe; the ghostly etchings
seen on the cosmic background radiation; quasars and their evolution;
and galaxy birth. This fascinating and accessible account offers an
exceptional chance for the general audience to share in the excitement
of today's forefront research of the early Universe.
---------------------------------------------------------
Title: Experiments at Putre for the November 3 Total Solar Eclipse
Regimiento de Caballería Blindada No. 1 "Granaderos" Site of the
International Astronomical Union Expeditions
Authors: Pasachoff, J. M.
1995pist.conf....1P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Proceedings of the international symposium on the total solar
eclipse of November 3, 1994. Lake Titicaca, Bolivia, May 14-17, 1995
Authors: Raljevic, Mirko S.; Zaratti, Francesco; Pasachoff, Jay M.
1995pist.conf.....R Altcode: 1994QB544.94.E25...
No abstract at ADS
---------------------------------------------------------
Title: Textbooks and Electronic Media
Authors: Pasachoff, J. M.
1995HiA....10..170P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Astronomy, from the Earth to the universe
Authors: Pasachoff, Jay M.
1995aetu.book.....P Altcode: 1995QB45.P287......
No abstract at ADS
---------------------------------------------------------
Title: An Upper Limit for the Deuterium Abundance in the Halo Star
HD 140283
Authors: Lubowich, D. A.; Pasachoff, Jay M.; Galloway, Robert P.;
Kurucz, R. L.; Smith, Verne V.
1994AAS...185.9805L Altcode: 1994BAAS...26.1479L
Because of the possible enhanced deuterium abundance of D/H =
2.5 10(-4) (the ISM D/H = 1.65x10(-5) ) recently reported in quasar
absorption spectra, we searched for the D_alpha line at 6561 A in the
metal-poor halo star HD 140283 (G2IV, [Fe/H] = -2.6; T<SUB>eff</SUB>=
5700K). We observed HD 140283 using the .9m KPNO coude feed and the
2.7m McDonald Observatory telescopes with echelle spectrographs
having a resolution Delta lambda = .05 A/pixel with S/N= 200 and
Delta lambda = .11 A/pixel with S/N = 600 respectively. We did not
detect the D_alpha line and compared our results to model atmosphere
calculations for this star. We estimate an upper limit of D/H <
1x10(-5) which is smaller than the primordial or and Early Galactic
D/H = 8x10(-5) . Since D is destroyed via reactions with protons at T
> 5x10(5) K, the atmospheric deuterium has probably been destroyed
during the pre-main sequence convection phase. Because (7) Li, (9)
Be, and (11) B have all been detected in this star (Li/H=1.5x10(-10)
and B/H=2.9x10(-12) ) and Li is destroyed at T > 2.5x10(6) K, the
temperature at the bottom of the pre-main sequence convection zone is
1x10(6) K < T < 2.5x10(6) .K
---------------------------------------------------------
Title: An answer to an earlier question
Authors: Pasachoff, Jay M.
1994PhTea..32..453P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Books-Received - the Cambridge Eclipse Photography Guide -
how and where to Observe and Photograph Solar and Lunar Eclipses
Authors: Pasachoff, J. M.; Covington, M. A.
1994Sci...264..297P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The Farthest Things in the Universe
Authors: Pasachoff, J. M.; Spinrad, H.; Osmer, P. S.; Cheng, E. S.
1994ftu..book.....P Altcode: 1994QB43.2.F37.....
Report of a symposium held at the American Association for the
Advancement of Science yearly meeting.
---------------------------------------------------------
Title: Coronal Morphology and Heating Mechanism Observations at
Total Eclipses Through 1992
Authors: Pasachoff, J. M.
1994scs..conf..523P Altcode: 1994IAUCo.144..523P
The author describes the change of overall coronal morphology over
the sunspot cycle, using most recently the total eclipse of 30 June
1992. He describes a series of eclipse observations meant to test a
model of coronal heating via surface Alfvén waves by searching for
1 Hz coronal oscillations in coronal loops in the green line.
---------------------------------------------------------
Title: Journey through the universe
Authors: Pasachoff, Jay M.
1994jtu..book.....P Altcode: 1994QB45.P293......
No abstract at ADS
---------------------------------------------------------
Title: Total Solar Eclipses, 1994 - 1999
Authors: Pasachoff, J. M.
1994scs..conf..579P Altcode: 1994IAUCo.144..579P
The author summarizes total solar eclipses that will occur during the
1990s. These eclipses will provide several favorable opportunities to
provide coronal and other solar observations not only for intrinsic
data reduction but also to compare with observations obtained from a
variety of spacecraft.
---------------------------------------------------------
Title: DCN in the 50 km/s Galactic Center SGR A Molecular Cloud:
Confirmation of the existence of deuterium in the Galactic Center
Authors: Lubowich, D. A.; Pasachoff, Jay M.; Balonek, Thomas J.;
Tremonti, Christy P.; Galloway, Robert P.; Mancuso, Ann
1993AAS...18311608L Altcode: 1993BAAS...25R1467L
We confirm the presence of deuterium in the Galactic Center Sgr A cloud
(tentative detection by Penzias (ApJ, 228, 430, 1979) with T_a(*) =
0.02 Kq 0.15 K) by observing the 1-0 and 2-1 lines of DCN in the "50
km/s" Galactic Center molecular cloud (M-0.02-.07) using the NRAO 12-m
telescope. We used the 3-mm and 2-mm SIS receivers in position switching
mode with 1 MHz filters, 256 MHz bandwidth, 4.1 km/s resolution at
the DCN 1-0 transition, and a typical T sys = 400K. We observed a
Gaussian line peak intensity T_r(*) and integrated Gaussian intensity
of 0.061 Kq.007 K, 2.0 K-km/s; and 0.042 Kq.02 K, 0.91 K-km/s for
the optically thin 1-0 and 2-1 DCN lines, respectively. The DCN was
concentrated along the north-south ridge observed in other molecules
in this cloud. We also observed H13CN, HC15N, HNC, DNC and HCO+ at the
position of the DCN 1-0 peak. From the DCN/H13CN we estimate DCN/HCN
= .005. The inferred D/H is estimated to be less than the local ISM
value of 2 x 10(-5) , but is sensitive to the chemistry and physical
conditions in the molecular cloud. These results imply that deuterated
molecules D are not significantly enhanced in the GC molecular clouds
and is consistant with the upper limits for atomic D obtained for the
GC molecular clouds (Lubowich, Anantharamaiah, and Pasachoff, ApJ,
345, 770, 1989). The DCN/HCN we obtained is similar to that of the
hot core of Orion so that D might be enhanced by fractionation and
the sublimation of fossil D from grains. If there are no Galactic
sources of D, then each generation of stars reduces the ISM D/H via
astration and the observed D is the primordial abundance reduced by
astration and mixing and possibly enhanced by the infall of primordial
matter. If the rate of astration is faster in the GC as suggested by
models of chemical evolution, then infall of primordial matter is a
likely source of the GC deuterium.
---------------------------------------------------------
Title: Curriculum Projects and their Effects on Astronomy Education
Authors: Pasachoff, Jay M.
1993AAS...183.6101P Altcode: 1993BAAS...25.1389P
National curriculum projects can have a long-lasting and widespread
effect on the teaching of astronomy in schools and thus on the supply of
astronomers and on knowledge of astronomy among the general public. For
example, the omission of astronomy as a requirement in 1893 by the
Committee of Ten (J.L. Bishop in Pasachoff and Percy, The Teaching
of Astronomy, Proc. IAU Colloq 105) and the fact that an astronomer
was not included on the committee has had major and long-lasting
consequences to the detriment of astronomy. Thus it is important for
us to become familiar with a set of curriculum projects that are now
being intensively worked on. They include the American Association for
the Advancement of Sciences Project 2061: Science for All Americans,
the National Science Teachers Association's Scope, Sequence, and
Coordination of Secondary-School Science Education, and the National
Committee on Science Education Standards and Assessment's National
Science Education Standards, the last under the aegis of the National
Research Council. We will discuss these projects and their impacts on
astronomy with principal participants James Rutherford for the AAS,
Russell Aiuto for the NSTA, and Ken Hoffmann for the NRC/NCSESA.
---------------------------------------------------------
Title: Coronal Images from the 1984 Solar Eclipse
Authors: Pasachoff, Jay M.; Reardon, Kevin P.; MacKenty, John W.
1993SoPh..146..405P Altcode:
We present digitized photographs of the white-light solar corona
taken during the total solar eclipse of 22-23 November, 1984, on both
calibrated black-and-white film and on color film. Conditions on site
in Hula, Papua New Guinea, were exceptionally clear. The color image
was used to produce an isophotal map of the inner corona, from which
a flattening coefficient of 0.23 was measured. The black-and-white
image was enhanced through a digital radial filter. Our images are the
best processed images available from the 1984 eclipse and so provide
important data for synoptic observations.
---------------------------------------------------------
Title: Books-Received - Mcgraw-Hill Encyclopedia of Astronomy - ED.2
Authors: Parker, S. P.; Pasachoff, J. M.
1993Sci...261.1189P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Rediscovering the Color of the Crab Nebula
Authors: Malin, David; Pasachoff, Jay M.
1993S&T....86...43M Altcode: 1993S&T....86a..43M
No abstract at ADS
---------------------------------------------------------
Title: CCD Observations of SN1993J in M81 from the Keck Northeast
Astronomy Consortium
Authors: Benson, P. J.; Little-Marenin, I. R.; Herbst, W.; Salzer,
J. J.; Vinton, G.; Elmegreen, D.; Chromey, F.; Balonek, T. J.; Strom,
C.; Tremonti, C.; Hanson, G. J.; Ratcliff, S.; Winkler, P. F.; Gloria,
K.; Kwitter, K.; Pasachoff, J. M.; Partan, J.; Crawford, F.; Elmegreen,
B.; Wells, L.; Tweedy, R.
1993AAS...182.2916B Altcode: 1993BAAS...25..835B
We present UBVRI photometry for SN 1993J, as well as data on its likely
progenitor. The post-explosion data were obtained with CCDs attached
to telescopes (0.4 to 0.6m) on the campuses of the Keck Northeast
Astronomy Consortium (KNAC) and on the Burrell Schmidt telescope of
the Warner and Swasey Observatory, Case Western Reserve University,
at KPNO by the authors and their undergraduate students. We have
obtained a fairly well-sampled light curve of the early stages in the
outburst, including the rapid decay (0.30 magnitude per day at V) from
the initial maximum and the subsequent slower rise to the secondary
maximum. The position of the supernova, as measured on our images
agrees to within 0.1 arc-sec with the position of a faint, apparently
stellar image, taken with the 0.9m telescope at KPNO on 1992 October
2. The brightness of this object (Perelmuter, IAUC 5736; Filippenko,
IAUC 5737; Humphreys et al., IAUC 5739) are consistent with its being a
late-type supergiant. A series of images of M81 taken in 1992 November
and 1993 February are analyzed to provide further constraints on the
likely progenitor and its photometric behavior in the months before
its explosion. We acknowledge the generous support of the W. M. Keck
Foundation for providing the CCD cameras and workstations and for
their support of astronomy at the KNAC institutions.
---------------------------------------------------------
Title: McGraw-Hill Encyclopedia of Astronomy
Authors: Parker, S.; Pasachoff, J. M.
1993mhea.book.....P Altcode: 1993QB14.M3725.....
A wide-ranging one-volume encyclopedia of astronomy; extracted from
the McGraw-Hill Encyclopedia of Science and Technology
---------------------------------------------------------
Title: The Cambridge eclipse photography guide : how and where to
observe and photograph solar and lunar eclipses
Authors: Pasachoff, Jay M.; Covington, Michael A.; Espenak, Fred
1993cepg.book.....P Altcode: 1993QB121.C69......
Eclipses of the 1990s and how to observe them.
---------------------------------------------------------
Title: Books-Received - a Field Guide to the Stars and Planets
Authors: Pasachoff, J. M.
1993Sci...260Q.706P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book Review - Exercises in Practical Astronomy Using
Photographs
Authors: Pasachoff, J. M.
1992JRASC..86..162P Altcode: 1992JRASC..86..162B
No abstract at ADS
---------------------------------------------------------
Title: Book-Review - the Teaching of Astronomy
Authors: Pasachoff, J. M.; Percy, J. R.
1992JBAA..102..175P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The 1816 Solar Eclipse and the Comet 1811I in Linnell's
Astronomical Album
Authors: Olson, R. J. M.; Pasachoff, J. M.
1992JHA....23..121O Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The great eclipse.
Authors: Pasachoff, J. M.
1992NaGe..181...30P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Unified units
Authors: Pasachoff, J. M.
1992Obs...112...15P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Williams College, Hopkins Observatory, Williamstown,
Massachusetts 01267. Report for the period Jul 1990 - Jul 1991.
Authors: Pasachoff, J. M.
1992BAAS...24..653P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Stars and planets
Authors: Pasachoff, Jay M.; Menzel, Donald H.
1992stpl.book.....P Altcode: 1992QB64.P37.......
No abstract at ADS
---------------------------------------------------------
Title: Journey through the universe
Authors: Pasachoff, Jay M.
1992jtun.book.....P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book-Review - Journey Through the Universe
Authors: Pasachoff, J. M.
1992Natur.355..407P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Save the U.S.NAVAL-OBS. Eclipse Circulars
Authors: Pasachoff, J. M.
1991S&T....82..342P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The Williams College 1991 Total Solar Eclipse Expedition
Authors: Pasachoff, J. M.
1991BAAS...23.1443P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The CUREA 1992 Summer Program in Astrophysics at Mount Wilson
Observatory
Authors: Snider, J.; Bracher, K.; Briggs, J.; Mickelson, M.; Mitchell,
W., Jr.; Pasachoff, J.; Snodgrass, H.; Yorka, S.
1991BAAS...23.1437S Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The Teaching of Astronomy: International Astronomical Union
Colloquium 105
Authors: Pasachoff, Jay M.; Percy, John R.; French, Richard G.
1991AmJPh..59..667P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The Sun - a Star Close UP
Authors: Pasachoff, J. M.
1991Mercu..20...66P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Access to Contemporary Research Results for Teachers of
Astronomy Courses on the School and University Levels
Authors: Pasachoff, J. M.
1991BAAS...23..930P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book-Review - Astronomy - from the Earth to the Universe
Authors: Pasachoff, J. M.
1991S&T....81Q.279P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Daylight savings.
Authors: Pasachoff, J. M.
1991PhTea..29R..71P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Fabry-Pérot line profiles in the λ5303 å and λ6374 å
coronal lines obtained during the 1983 Indonesian eclipse
Authors: Chandrasekhar, T.; Desai, J. N.; Ashok, N. M.; Pasachoff,
Jay M.
1991SoPh..131...25C Altcode:
During the total solar eclipse of 11 June, 1983, an imaging dual-channel
Fabry-Pérot interferometer was used to obtain line profiles
simultaneously in the green λ5303 Å [Fe XIV] and the red λ6374 Å
[Fe X] coronal lines at various positions in the corona. Extensive
microdensitometry followed by multi-Gaussian curve-fitting analysis
has resulted in the determination of coronal temperatures and velocity
separations between different pockets of coronal gas in the line
of sight over a large extent of the corona. Fewer high temperature
zones are to be found in the corona of 1983 compared with our similar
green-line measurements of the solar maximum corona of 1980. The
data are consistent with a temperature maximum occurring at 1.2
R<SUB>⊙</SUB>, as found at the 1980 eclipse, but our new data are
insufficient to observe farther out than this radius and so determine
the position of a maximum. The velocity field in the corona at the 1983
eclipse is less structured compared with that at the 1980 eclipse and
is mainly confined to the zone 20-30km s<SUP>−1</SUP>.
---------------------------------------------------------
Title: Williams College, Hopkins Observatory, Williamstown,
Massachusetts 01267. Report for the period Jul 1989 - Jun 1990.
Authors: Pasachoff, J. M.
1991BAAS...23..791P Altcode: 1991BAAS...23..791.
No abstract at ADS
---------------------------------------------------------
Title: Measurements of 1-Hz Coronal Oscillations at Total Eclipses
and Their Implications for Coronal Heating
Authors: Pasachoff, J. M.
1991mcch.conf...25P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Undergraduate Symposium on Research in Astronomy
Authors: Benson, Priscilla J.; Pasachoff, Jay M.; Wong, Alex K.
1991usra.conf.....B Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Astronomy, from the earth to the universe
Authors: Pasachoff, Jay M.
1991aeu..book.....P Altcode: 1991QB45.P287......
No abstract at ADS
---------------------------------------------------------
Title: Historical Comets Over Bavaria: the Nuremberg Chronicle
and Broadsides
Authors: Olson, R. J. M.; Pasachoff, J. M.
1991ASSL..167.1309O Altcode: 1991cphe.conf.1309O; 1991IAUCo.116.1309O
No abstract at ADS
---------------------------------------------------------
Title: The Solar Corona Over the Recent Saros
Authors: Pasachoff, Jay M.
1991LNP...380..285P Altcode: 1991sacs.coll..285P; 1991IAUCo.130..285P
We are now at both the maximum of the solar activity cycle and at the
most populated part of the saros. I discuss the solar corona over
the recent saros and its changes with the solar activity cycle. We
consider the scientific value of eclipse studies and how they relate
to other ongoing coronal studies on the sun and other stars.
---------------------------------------------------------
Title: Observing Solar Eclipses
Authors: Pasachoff, J.
1991atq..conf...67P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Coronal Structures and the Sunspot Cycle
Authors: Pasachoff, Jay M.
1991LNP...387..283P Altcode: 1991fpsa.conf..283P
Several solar eclipses must be observed to study the, corona at
different phases of the solar-activity cycle. I describe a series
of coronal observations at various eclipses over the most recent
saros. The most recent experiment studies a mechanism of coronal heating
by measuring high-frequency intensity oscillations in coronal loops in
the green line. I also describe an application of the monthly variation
in the daily sunspot numbers to the solar-neutrino problem.
---------------------------------------------------------
Title: Book Review: The restless sun. By Donat G. Wentzel. Smithsonian
Institution Press, Washington DC, 1989. 279 pp., including
indexes. ISBN 0-87474-982-4. $27.95 cloth
Authors: Pasachoff, Jay M.
1990Icar...88..262P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book-Review - the Teaching of Astronomy
Authors: Pasachoff, J. M.
1990S&T....80..381P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Coronal Velocities from Fabry-Perot Line Profiles at the
1983 Eclipse
Authors: Pasachoff, J. M.; Chandrasekhar, T.; Desai, J. N.; Ashok,
N. M.
1990BAAS...22.1196P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book-Review - the Teaching of Astronomy
Authors: Pasachoff, J. M.; Percy, J. R.
1990Sci...249..574P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book-Review - the Teaching of Astronomy
Authors: Pasachoff, J. M.; Percy, J. R.
1990JBAA..100R.103P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Urania Observed
Authors: Fernandez, Rafael; Pasachoff, Jay M.; Volz, Robert
1990teas.conf..431F Altcode: 1990IAUCo.105..431F
No abstract at ADS
---------------------------------------------------------
Title: Fabry-Perot Interferogram Profiles in Lambda 5303 IN Relation
to Coronal Structures - 1980 and 1983 Eclipses
Authors: Desai, J. N.; Raju, K. P.; Chandrasekhar, T.; Ashok, N. M.;
Pasachoff, J. M.
1990IAUS..142..251D Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Astronomy in American Textbooks
Authors: Pasachoff, Jay M.
1990teas.conf..201P Altcode: 1990IAUCo.105..201P
No abstract at ADS
---------------------------------------------------------
Title: Book-Review - the Teaching of Astronomy
Authors: Pasachoff, J. M.; Percy, J. R.
1990AstQ....7..254P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Peterson first guide to the solar system
Authors: Pasachoff, Jay M.; Peterson, Roger Tory; Tirion, Wil
1990pfgs.book.....P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The teaching of astronomy
Authors: Pasachoff, Jay M.; Percy, John R.
1990teas.conf.....P Altcode: 1990IAUCo.105.....P
This book stems from the proceedings of the International Astronomical
Union Colloquium 105. Every facet of the teaching of astronomy is
explored by the contributors. Courses, training and teaching techniques
form a large sector of the book. Practical information on computers,
textbooks and astronomical equipment is given, linking in with chapters
on student projects and teaching techniques. The philosophical aspects
and the history of astronomy are described in a chapter entitled
astronomy and culture. Popularisation of astronomy is discussed
including the role of planetariums and the contribution of amateur
astronomers. This comprehensive and well illustrated book offers a
unique overview of international teaching technology and expertise
that will serve as a lasting guide to astronomers involved in education.
---------------------------------------------------------
Title: Is Comet p/ Halley of 684-A.D. Recorded in the Nuremberg
Chronicle
Authors: Olson, R. J. M.; Pasachoff, J. M.
1989JHA....20..171O Altcode:
No abstract at ADS
---------------------------------------------------------
Title: A Search for Localized Sources of Noncosmological Deuterium
near the Galactic Center
Authors: Lubowich, D. A.; Anantharamaiah, K. R.; Pasachoff, Jay M.
1989ApJ...345..770L Altcode:
The VLA at the 92 cm D I hyperfine transition was used to search
for a possible localized concentration of atomic deuterium near the
Galactic center over a velocity range of + or - 180 km/s. The search
yielded an upper limit for the D column density N(D) = 7.78 x 10 to
the 16th T(s)/sq cm where T(s) is the spin temperature of the D I
hyperfine lines. For the smaller velocity range of + or - 30 km/s, a
more sensitive upper limit of N(D) = 3.12 x 10 to the 16th T(s)/sq cm is
obtained. If D is associated with the H I clouds to the Galactic center,
an upper limit for the D/H ratio of 0.0043 is obtained for the clouds
at V = 20 km/s and 50 km/s. If a significant fraction of the D exists
in atomic form in molecular clouds, the upper limits are 1.2 x 10 to
the -7th for the V = 20 km/s molecular cloud near the Galactic center
and 8.3 x 10 to the -7th for the V = 50 km/s molecular cloud near the
Galactic center. These results are consistent with the D observed in
the Galactic center and the ISM being primarily cosmological in origin.
---------------------------------------------------------
Title: CUREA: The Consortium for Undergraduate Research and Education
in Astronomy
Authors: Snider, J.; Bracher, K.; Meyers, K.; Mickelson, M.; Mitchell,
W., Jr.; Naftilan, S.; Pasachoff, J.; Snodgrass, H.; Yorka, S.;
Zook, A.
1989BAAS...21.1065S Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Astrophysics of the Sun
Authors: Zirin, Harold; Pasachoff, Jay M.
1989AmJPh..57..669Z Altcode:
No abstract at ADS
---------------------------------------------------------
Title: A Search for Remnant Planetary Nebulae around Hot sdO Stars
Authors: Kwitter, Karen B.; Massey, Philip; Congdon, Charles W.;
Pasachoff, Jay M.
1989AJ.....97.1423K Altcode:
Spectroscopic and imaging searches for nebular emission associated
with a sample of hot subdwarf O (sdO) stars have been carried out. Of
45 stars searched, no evidence of such nebulosity is found in 44. The
single exception is RWT 152, around which a planetary nebula had been
discovered previously. These negative results place constraints on
the evolutionary history of these stars.
---------------------------------------------------------
Title: Hopkins Observatory, Williams College, Williamstown,
Massachusetts 01267. Report for the 1987 - 1988 academic year.
Authors: Pasachoff, J. M.
1989BAAS...21..680P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The need to observe the distribution of interstellar deuterium.
Authors: Pasachoff, J. M.; Vidal-Madjar, A.
1989ComAp..14...61P Altcode:
The abundance of deuterium is linked with nucleosynthesis in the first
1000 seconds of the history of the universe. Though the interstellar
deuterium abundance is known in the solar neighborhood from ultraviolet
studies of Lyman lines, it is poorly known in other parts of the
Galaxy. Determining the deuterium abundance gradient in the Galaxy,
or extending observations to distant galaxies, should resolve the
question of non-cosmological deuterium formation and should give
cosmological insights.
---------------------------------------------------------
Title: Contemporary astronomy
Authors: Pasachoff, Jay M.
1989coas.book.....P Altcode: 1989QB45.P29.......
No abstract at ADS
---------------------------------------------------------
Title: Teaching about the planets at (large) scale
Authors: Pasachoff, Jay M.
1989PhTea..27...38P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book-Review - Peterson First Guide to Astronomy
Authors: Pasachoff, J. M.; Tirion, W.; Brickman, R.; Byrd, D.
1989S&T....77...38P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Deuterium in the Universe (May, 1974)
Authors: Pasachoff, Jay M.; Fowler, William A.
1989ppc..book..151P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book-Review - Peterson First Guides - Astronomy
Authors: Pasachoff, J. M.; Hilditch, R.
1988Obs...108..250P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Up-to-date astronomy revisited
Authors: Pasachoff, Jay M.
1988PhTea..26..424P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Historical Comets of the "Nuremberg Chronicle"
Authors: Pasachoff, J. M.; Olson, R. J. M.
1988BAAS...20..991P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: A Search for Remnant Planetary Nebulae Around Hot Subdwarf
O Stars
Authors: Kwitter, K. B.; Massey, P.; Congdon, C. W.; Pasachoff, J. M.
1988BAAS...20.1052K Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book-Review - a Field Guide to Stars and Planets
Authors: Menzel, D. H.; Pasachoff, J. M.; Tirion, W.; Soltynski, M.
1988MNSSA..47..161M Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Peterson first guide to astronomy maps
Authors: Pasachoff, Jay M.; Peterson, Roger Tory; Tirion, Wil;
Brickman, Robin
1988pfga.book.....P Altcode: 1988QB46.P376......
No abstract at ADS
---------------------------------------------------------
Title: The Peterson first guide to astronomy. A simplified field
guide to the stars, planets and the universe.
Authors: Pasachoff, J. M.
1988pfgt.book.....P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: New telescopes view the sky.
Authors: Pasachoff, J. M.
1988itod....2....6P Altcode:
Concerning the 4.2-m William Herschel Telescope, Roque de los Muchachos
Observatory, La Palma, Canary Islands.
---------------------------------------------------------
Title: New Information on Comet p/ Halley as Depicted by Giotto DI
Bondone and Other Western Artists
Authors: Olson, R. J. M.; Pasachoff, J. M.
1987A&A...187....1O Altcode:
Artists' depictions of comets provide the only visual evidence of
historical comets, most notably of Halley's Comet. In this paper we
discuss the visual evidence of comet P/Halley at several passages
through that of 1301 and compare it with descriptions and modern
images. Since it was first recognized that Giotto di Bondone painted a
comet in place of the Star of Bethlehem and suggested that this was a
portrait of the 1301 apparition of comet Halley (Olson, 1979), a great
deal of new information has come to light. We present a synopsis of
the textual, visual, and astronomical evidence to support the theory
that when Giotto painted his comet in the Scrovegni Chapel he was
reflecting his viewing of Comet Halley in 1301.
---------------------------------------------------------
Title: A Search for Localized Sources of Deuterium Near the Galactic
Center
Authors: Lubowich, D. A.; Anantharamaiah, K. R.; Pasachoff, J. M.
1987BAAS...19Q1076L Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Addendum - High-Frequency Oscillations in the Corona Observed
at the 1983 Eclipse
Authors: Pasachoff, J. M.; Ladd, E. F.
1987SoPh..110..412P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Sesquicentennial of Williams College's Hopkins Observatory
Authors: Pasachoff, J. M.; Kwitter, K. B.; Friend, D.
1987BAAS...19R1065P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: High-Frequency Oscillations in the Corona Observed at the
1983 Eclipse
Authors: Pasachoff, Jay M.; Ladd, Edwin F.
1987SoPh..109..365P Altcode:
We detected excess oscillatory power at 0.25-2.0 Hz in a coronal loop
in the 1983 Indonesian total solar eclipse. In this second-generation
experiment enlarging upon the work of Pasachoff and Landman (1984),
we observed in two frequency channels, one coronal and one continuum,
to monitor atmospheric and instrumental effects. We briefly discuss
the effects of an oscillation near 1 Hz on the coronal heating problem.
---------------------------------------------------------
Title: Book-Review - Astronomy - from the Earth to the Universe
Authors: Pasachoff, J. M.
1987S&T....74..263P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Timing of the 1984 Total Solar Eclipse and the Size of the Sun
Authors: Pasachoff, Jay M.; Nelson, Brant O.
1987SoPh..108..191P Altcode:
We report accurate timing of second and third contacts made from
videotape of the total solar eclipse of 23 November, 1984, observed in
Papua New Guinea. The magnitude of the discrepancies between predicted
and observed times indicates that the secular change in the size of
the Sun reported by some observers is within the uncertainty.
---------------------------------------------------------
Title: Fabry-Perot Line Profiles in 5303A and 6374A Coronal Lines
Obtained during the 1983 Eclipse
Authors: Sekhar, T. C.; Desai, J. N.; Ashok, N. M.; Pasachoff, J. M.
1987BASI...15R..18S Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Astronomy, from the earth to the universe
Authors: Pasachoff, Jay M.
1987afet.book.....P Altcode: 1987QB45.P287......
No abstract at ADS
---------------------------------------------------------
Title: Interpreting Quasar Redshifts
Authors: Maltby, Per; Pasachoff, Jay M.; Kierein, John
1987PhT....40c.110M Altcode:
No abstract at ADS
---------------------------------------------------------
Title: New Information on Comet Halley as Depicted by Giotto DI
Bondone and Other Western Artists
Authors: Olson, Roberta J.; Pasachoff, Jay M.
1986ESASP.250c.201O Altcode: 1986ehc3.conf..201O
Artists' depictions of comets provide the only visual evidence of
historical comets, most notably of Halley's comet. The authors discuss
the visual evidence of comet Halley at several passages (684, 1066,
1145, 1222, 1301, 1456, 1531, 1682, 1759 and 1835) and compare these
with descriptions and modern images. They also include their own
images made with the Canada-France-Hawaii Telescope. Since it was
first recognized that Giotto di Bondone painted a comet in place of
the Star of Bethlehem and suggested that this was a portrait of the
1301 apparition of comet Halley.
---------------------------------------------------------
Title: A scientist's view of cosmology
Authors: Pasachoff, Jay M.
1986PhTea..24..569P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book-Review - a Brief View of Astronomy
Authors: Pasachoff, J. M.; McNally, D.
1986SSRv...44..408P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book-Review - Contemporary Astronomy
Authors: Pasachoff, J. M.; Hill, P. W.
1986Obs...106..121P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Historical Studies of Halley's and Other Comets via Artists'
Depictions
Authors: Pasachoff, J. M.; Olson, R. J. M.
1986BAAS...18..792P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book-Review - Contemporary Astronomy 3RD-ED
Authors: Pasachoff, J.
1986Mercu..15...94P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The X-Ray Universe
Authors: Tucker, Wallace; Giacconi, Riccardo; Pasachoff, Jay M.
1986PhT....39f..87T Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Gamma Ray Astronomy
Authors: Hiller, Rodney; Pasachoff, Jay M.
1986PhT....39g..71H Altcode:
No abstract at ADS
---------------------------------------------------------
Title: A brief view of astronomy
Authors: Pasachoff, Jay M.
1986bva..book.....P Altcode: 1986QB43.2.P357....
No abstract at ADS
---------------------------------------------------------
Title: Periodic Comet Halley (1982i)
Authors: Hua, T.; Grundseth, B.; Pasachoff, J. M.; Ladd, E.; Schroder,
M. F.; Pastoriza, M.; Dottori, H.; Kepler, S. O.; Bergmann, T. S.;
Ducati, J. R.; Livi, S. H. B.; Schmidt, A.; Bonatto, C.; Costa,
R. D. D.; Kosai, H.; Bortle, J.; Merlin, J. -C.; Krisciunas, K.;
Cavagna, M.; Keen, R.; Green, D. W. E.
1985IAUC.4126....2H Altcode:
T. Hua and B. Grundseth, Canada-France-Hawaii Telescope; and
J. M. Pasachoff and E. Ladd, Hopkins Observatory, report observations
of P/Halley on Oct. 23.3 UT with the photon-counting camera at the
f/8 Cassegrain focus of the 3.6-m CFHT on Mauna Kea. Images with
the CN (387.1 nm) filter show diffuse emission with central area 30"
in size. Continuum emission through a 0.8-nm filter at 500.7 nm and
a 0.47-nm H-alpha filter fills the field and is more peaked as is CO+
emission through the 426-nm P/Halley standard filter. M. F. Schroder,
M. Pastoriza, H. Dottori, S. O. Kepler, T. S. Bergmann, J. R. Ducati,
S. H. B. Livi, A. Schmidt, C. Bonatto and R. D. D. Costa, Departamento
de Astronomia, Universidade Federal do Rio Grande do Sul, Brazil, find
B = 15.3 and V = 14.8 (both +/- 0.2, total magnitude) on Sept. 22.29 UT
from plates taken at the 1.6-m telescope of the Observatorio Astrofisico
Brasileiro. H. Kosai, Tokyo Astronomical Observatory, reports V = 14.0
with a 30" diaphragm on the 0.91-m Okayama telescope on Sept. 13.67
UT. Total visual magnitude estimates: Oct. 7.39 UT, 11.0 (J. Bortle,
Stormville, NY, 0.32-m reflector); 10.94, 11.0 (J.-C. Merlin, Le
Creusot, France, 0.40-m reflector); 14.52, 10.8 (K. Krisciunas, Hilo,
HI, 0.15-m reflector); 17.95, 10.2 (M. Cavagna, Valcava, Italy, 20 x 80
binoculars); 20.40, 9.1 (R. Keen, Mt. Thorodin, CO, 8 x 40 binoculars);
24.38, 8.5 (D. W. E. Green, Oak Ridge Observatory, 20 x 80 binoculars).
---------------------------------------------------------
Title: The Comet Book
Authors: Chapman, Robert D.; Pasachoff, Jay M.
1985PhTea..23..387C Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Contemporary astronomy
Authors: Pasachoff, Jay M.
1985coas.book.....P Altcode: 1985QB45.P29.......
No abstract at ADS
---------------------------------------------------------
Title: The Invisible Unviverse: Probing the Frontiers of Astrophysics
Authors: Field, George B.; Chaisson, Eric J.; Pasachoff, Jay M.
1985PhT....38j.107F Altcode:
No abstract at ADS
---------------------------------------------------------
Title: A brief view of astronomy.
Authors: Pasachoff, J. M.
1985bva..book.....P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The Planetary Nebula around the sdO Star RWT 152
Authors: Pasachoff, J. M.; Kwitter, K. B.; Massey, P.
1984BAAS...16..994P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book-Review - a Field Guide to the Stars and Planets
Authors: Menzel, D. H.; Pasachoff, J. M.
1984S&T....68..227M Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Coelostat and heliostat: alignment and use for eclipse and
other field purposes
Authors: Pasachoff, Jay M.; Livingston, William C.
1984ApOpt..23.2803P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Coelostat and heliostat: Theory of alignment
Authors: Demianski, M.; Pasachoff, J. M.
1984SoPh...93..211D Altcode:
For perfectly aligned heliostats and coelostats tracking at the
solar rate and half the solar rate, respectively, the solar beam
has no translational motion. But, particularly in the field at
eclipses, it is not possible to align heliostats and coelostats with
infinite precision. We derive the effect of small misalignments on
the translational motion of the beam, and give tables to allow the
calculation of the accuracy to which the instruments must be mounted and
adjusted to attain a desired accuracy over a given duration. Further,
we show how to derive the necessary adjustments to improve alignment,
given measurements of the tracking error.
---------------------------------------------------------
Title: High Frequency Coronal Oscillations and Coronal Heating
Authors: Pasachoff, J. M.; Landman, D. A.
1984SoPh...90..325P Altcode:
At the 1980 total solar eclipse, we searched for high-frequency
(0.1-2 Hz) oscillations in the intensity of the 5303-Å coronal
green line, as a test of predictions of theories of coronal heating
via magnetohydrodynamic waves. Portions of the image 2.5- or 5-arc
sec across were fed to cooled photomultipliers using fiber-optic
probes. We detected excess power in Fourier transforms of the data
for the region between 0.5 and 2 Hz at the level of 1% or 2% of the
incident power. Such oscillations could be associated with Alfvén
waves that are trapped on loops a few thousand kilometers long or
with fast waves that are trapped on loops a few thousand kilometers
in diameter. Additional observations at the 1983 eclipse are planned
to resolve atmospheric and instrumental contributions.
---------------------------------------------------------
Title: Fabry-Perot interferometric observations of the coronal red
and greenlines during the 1983 Indonesian eclipse.
Authors: Chandrasekhar, T.; Ashok, N. M.; Desai, J. N.; Pasachoff,
J. M.; Sivaraman, K. R.
1984ApOpt..23..508C Altcode:
A dual-channel Fabry-Perot interferometric system was used to study
simultaneously the coronal emission lines at 5303 Å (Fe XIV) and at
6374 Å (Fe X). Initial results indicate an emission corona confined
largely within 1.2 R_sun;. Doppler temperatures derived from the
width of the 5303-Å line appear to be appreciably lower than similar
temperatures determined during the solar-maximum eclipse of 1980.
---------------------------------------------------------
Title: Book-Review - Astronomy - from the Earth to the Universe
Authors: Pasachoff, J. M.; Boyle, R. J.
1984S&T....68..423P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book-Review - Astronomy - from the Earth to the Universe
Authors: Pasachoff, J.
1984Mercu..13...91P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book-Review - a Field Guide to the Stars and Planets - ED.2
Authors: Menzel, D. H.; Pasachoff, J. M.
1984Natur.309..477M Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book-Review - a Field Guide to the Stars and Planets
Authors: Menzel, D. H.; Pasachoff, J. M.; de Jager, C.
1984SSRv...38..185M Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book-Review - Sun and Planetary System
Authors: Fricke, W.; Teleki, G.; Pasachoff, J. M.
1984ApL....24..129F Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book-Review - Teacher's Guide to Astronomy - from the Earth
to the Universe
Authors: Pasachoff, J. M.; van der Hucht, K. A.
1984SSRv...37..402P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book-Review - a Field Guide to the Stars and Planets - ED.2
Authors: Menzel, D.; Pasachoff, J.
1984Mercu..13S..86M Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book-Review - Astronomy from the Earth to the Universe
Authors: Pasachoff, J. M.; van der Hucht, K. A.
1983SSRv...36..420P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: On the Balmer: Paschen ratio in prominences
Authors: Pasachoff, Jay M.; Pilger, Eric J.; Platt, Stephen R.
1983SoPh...89...31P Altcode:
Vidicon data for the intensities of Balmer and Paschen lines for n =
11 to 18 indicate a line ratio within 1σ of the theoretical value of
3.27, calculated with the assumptions of an optically thin atmosphere
and angular momentum substates populated according to their statistical
weights. The observed value is not consistent with the value of 8
reported in some early work, or with the model that higher angular
momentum states have low populations.
---------------------------------------------------------
Title: POST-USE REVIEW: Astronomy: From the Earth to the Universe
Authors: Pasachoff, Jay M.; Marschall, Laurence A.
1983AmJPh..51.1054P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book-Review - Astronomy - from the Earth to the Universe
Authors: Pasachoff, J.
1983Sci...220..402P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book-Review - Astronomy - from the Earth to the Universe ED.2
Authors: Pasachoff, J.; Hughes, D. W.
1983Natur.302..186P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: A field guide to the stars and planets
Authors: Menzel, Donald Howard; Pasachoff, Jay M.
1983fgts.book.....M Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Space Astronomy on Videodisk
Authors: Pasachoff, Jay M.
1983S&T....65...32P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book-Review - Astronomy - from the Earth to the Universe
Authors: Pasachoff, J. M.
1983S&T....65Q.242P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Astronomy, from the earth to the universe
Authors: Pasachoff, Jay M.
1983afeu.book.....P Altcode: 1983QB45.P287......
No abstract at ADS
---------------------------------------------------------
Title: Teacher's guide to astronomy: from the earth to the universe.
Authors: Pasachoff, J. M.
1983tgta.book.....P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book-Review - Astronomy - from the Earth to the Universe - ED.2
Authors: Pasachoff, J.; Fraknoi, A.
1983Mercu..12...88P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book-Review - the Cambridge Encyclopedia of Earth Sciences
Authors: Smith, D. G.; Pasachoff, J. M.
1983S&T....65..234S Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book-Review - Contemporary Astronomy - ED.2
Authors: Pasachoff, J. M.
1982Natur.298..310P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Letters: Ikeya-Seki, Its
Authors: Seargent, David A. J.; Pasachoff, Jay M.
1982CNSMP..33....2S Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book Review: Invitation of Physics
Authors: Pasachoff, J. M.; Kutner, M.; Mewe, R.
1982SSRv...31..457P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Erratum - Book-Review - Our Cosmic Universe
Authors: Kraus, J.; Pasachoff, J.
1982S&T....63Q...5K Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book Review: Contemporary Astronomy
Authors: Pasachoff, J. M.; Houziaux, L.
1982SSRv...31..459P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book-Review - Contemporary Astronomy
Authors: Pasachoff, J. M.; Lestrade, J. P.
1982S&T....63..156P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Hopkins Observatory, Williams College, Williamstown,
Massachusetts 01267. Report for the 1980 - 1981 academic year.
Authors: Pasachoff, J. M.
1982BAAS...14..206P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Astronomical Data Bank - the Largest Optical Telescopes
Authors: Pasachoff, J.
1982Mercu..11..142P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Helium excitation in quiescent prominences.
Authors: Landman, D. A.; Bernat, A. P.; Pasachoff, J. M.
1981BAAS...13R.552L Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Helium Excitation in Quiescent Prominences
Authors: Landman, D. A.; Bernat, A. P.; Pasachoff, J. M.
1981BAAS...13..552L Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Hopkins Observatory, Williams College, Williamstown,
Massachusetts 01267. Report for the 1979 - 1980 academic year.
Authors: Pasachoff, J. M.; Kwitter, K. B.
1981BAAS...13..157P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book-Review - Invitation to Physics
Authors: Pasachoff, J. M.; Kutner, M. L.
1981S&T....62R.156P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Invitation to physics.
Authors: Pasachoff, J. M.; Kutner, M. L.
1981itp..book.....P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book-Review - Contemporary Astronomy
Authors: Pasachoff, J. M.
1981Sci...213.1002P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book-Review - Our Cosmic Universe
Authors: Kraus, J.; Pasachoff, J.
1981S&T....62..469K Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book-Review - Contemporary Astronomy
Authors: Pasachoff, J. M.
1981S&T....62..361P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Contemporary astronomy
Authors: Pasachoff, Jay M.
1981coas.book.....P Altcode: 1981QB45.P29.......
No abstract at ADS
---------------------------------------------------------
Title: Projects and Demonstrations in Astronomy
Authors: Tattersfield, Donald; Pasachoff, Jay M.
1981AmJPh..49...93T Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Preliminary Report of 1980 Eclipse - Coronal Oscillations
Experiment
Authors: Pasachoff, J. M.; Landman, D. A.
1980BASI....8..137P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: An Eclipse Search for 1-10 Hz Temporal Variations in Coronal
Loops
Authors: Pasachoff, J. M.; Landman, D. A.; Schierer, J. P.
1980BAAS...12Q.793P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Turbulence in the dust cloud L134 - High-resolution
observations of 6 centimeter formaldehyde absorption
Authors: Dickman, R. L.; Kutner, M. L.; Pasachoff, J. M.; Tucker, K. D.
1980ApJ...238..853D Altcode:
Observations of 6 cm formaldehyde absorption were made at high spatial
and velocity resolution toward the central regions of the dust cloud
Lynds 134. A least-squares fit to the hyperfine manifold of each
spectrum yielded precise υ<SUB>LSR</SUB> values at each position;
these show no evidence of positional variation. This suggests that
if previously observed smooth shifts in υ<SUB>LSR</SUB> (which occur
over a much larger portion of the cloud than observed here) are in fact
due to rotation, this rotation is not carried into the most heavily
obscured parts of the cloud. <P />The fit procedure also yielded precise
values for the line velocity dispersion at each position. These vary
significantly over the cloud core. These results are used to discuss
turbulent models of the cloud velocity field. In the absence of an
energy source, the resulting picture of the cloud must be regarded
as highly improbable. One or more embedded T Tauri stars undergoing
mass loss could account for the turbulent dissipation expected for
the cloud, and the presence of such stars is not observationally
excluded. The dynamical consistency of such a model remains to be
established, however. We also briefly discuss the observations in
terms of a systematic velocity field for the cloud. Subject headings:
interstellar: molecules nebulae: individual
---------------------------------------------------------
Title: Book-Review - Astronomy - from the Earth to the Universe
Authors: Pasachoff, J. M.; Hughes, D. W.
1980Natur.283..913P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book-Review - Astronomy - from the Earth to the Universe
Authors: Pasachoff, J. M.; Andrews, P. J.
1980Obs...100R..48P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book-Review - Astronomy now
Authors: Pasachoff, J. M.; Warasila, R. L.
1980ApL....20..148P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Hopkins-Observatory / Williams-College
Authors: Pasachoff, J. M.
1980BAAS...12..129P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book-Review - Astronomy now
Authors: Pasachoff, J. M.; Andrews, P. J.
1980Obs...100Q..48P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book-Review - Astronomy : from the Earth to the Universe
Authors: Pasachoff, J.
1980Mercu...9S..20P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book-Review - University Astronomy
Authors: Pasachoff, J. M.; Kutner, M. L.; Zimmermann, R. E.
1980S&T....60..229P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Some tests of astrology.
Authors: Pasachoff, J.
1980Mercu...9..137P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book-Review - Astronomy
Authors: Pasachoff, J. M.
1980Sci...207..174P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The Maximum Eclipse - 1980FEB16
Authors: Ohno, H.; Fujii, A.; Tomioka, H.; Sperling, N.; Marschall,
L. A.; Allan, R. P.; Lipschutz, S.; Brooks, E.; Gerber, L.; van den
Bergh, S.; van den Bergh, G.; Pasachoff, J.
1980S&T....59..383O Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Popular Open Universe
Authors: Pasachoff, J. M.
1980SciN..117..227P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Response to ”Astronomical meaning of a tropical year”
Authors: Pasachoff, Jay M.
1979AmJPh..47.1017P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Neutrinos for Interstellar Communication
Authors: Pasachoff, Jay M.; Kutner, Marc L.
1979CosSe...1....2P Altcode:
A method of interstellar communication employing neutrinos is
presented and a brief history of the discovery of the neutrino
is given. Advantages and disadvantages of neutrino communication
are discussed emphasizing both the high cost and the difficulty
in generating neutrino beams by means of proton beams impinging on
targets (steel or aluminum shields) in large accelerators. The deep
underwater muon and neutrino detection system is examined as well as
a block diagram describing the neutrino communication system.
---------------------------------------------------------
Title: IUE and the Search for a Lukewarm Corona
Authors: Pasachoff, J. M.; Linsky, J. L.; Haisch, B. M.; Boggess, A.
1979S&T....57..438P Altcode:
The use of the International Ultraviolet Explorer (IUE) to search
for stars having neither a hot corona nor a cool outer atmosphere,
but a lukewarm corona is outlined. An interactive computer system
permits extensive analysis of the data immediately after transmission
to earth, allowing the results of one exposure to influence the taking
of subsequent exposures. The observation program is illustrated for the
star HR 1099, noting that observations were taken while previous spectra
were being analyzed. Observations of many stars of spectral types G and
K lead to the construction of a border region on the Hertzsprung-Russell
diagram between stars with hot coronas and those with cool outer
atmospheres. Stars lying near this border region were then observed;
however, none with lukewarm coronas was found. The interactive control
facility in the satellite control room is considered an important
factor in the efficient implementation of the search procedure.
---------------------------------------------------------
Title: The future of the universe
Authors: Pasachoff, Jay M.
1979PhTea..17..291P Altcode:
Olber's paradox is discussed in terms of Hubble's law, and the
question of the closure of the universe is considered in light of
recent experimental observations. (AIP)
---------------------------------------------------------
Title: Laboratory Exercises in Astronomy -- Cepheid Variables and
the Cosmic Distance Scale
Authors: Pasachoff, Jay M.; Goebel, Ronald W.
1979S&T....57..241P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book-Review - Van-Nostrand Scientific Encyclopedia ED.5
Authors: Pasachoff, J.
1979ApL....20..112P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Teacher's guide to Astronomy, from the Earth to the universe
Authors: Pasachoff, Jay M.
1979tasg.book.....P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Repechage
Authors: Pasachoff, Jay M.
1979afeu.book...67P Altcode:
A method is discussed of enhancing student learning by providing an
opportunity for students to provide corrected answers to questions
gotten wrong on examinations, with up to half credit awarded
back. However, if the course is graded on a curve, if all students got
half credit back, their relative scores and thus their grades would
remain the same. The method thus provides an incentive for students
to participate in the repechage, a term from the sport of crew.
---------------------------------------------------------
Title: Piaget
Authors: Pasachoff, Jay M.
1979afeu.book...65P Altcode:
Teachers of astronomy often misinterpret the reliability of
Piaget's conclusions about concrete and abstract reasoning for
young students. This misinterpretation can result in interesting
material being excluded from teaching. The discussion here gives
some references and broader conclusions evaluating Piaget's work and
providing alternatives.
---------------------------------------------------------
Title: Book-Review - University Astronomy
Authors: Pasachoff, J.; Kutner, M. L.; Nicolson, I.
1979JBAA...90...87P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Hopkins Observatory, Williams College, Williamstown,
Massachusetts 01267. Report for the 1978 - 1979 academic year.
Authors: Pasachoff, J. M.
1979BAAS...11..128P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Astronomy, from the Earth to the universe
Authors: Pasachoff, Jay M.
1979afeu.book.....P Altcode: 1979QB45.P287......
No abstract at ADS
---------------------------------------------------------
Title: Contemporary Astronomy
Authors: Pasachoff, Jay M.
1978AmJPh..46.1084P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Spatial structure in lines in the 3398 3526 å region at the
extreme limb: Observation, identification and interpretation
Authors: Canfield, R. C.; Pasachoff, J. M.; Stencel, R. E.; Beckers,
J. M.
1978SoPh...58..263C Altcode:
We have obtained spectrograms of high spatial and spectral resolution
of the extreme solar limb, using the vacuum tower telescope of
Sacramento Peak Observatory. We have identified emission lines in
the range 3398-3526 Å, and classified them according to intensity,
spatial structure (intensity variation), and profile. Some lines show
spatial intensity variation; others do not. We show that this effect
is related to the abundance of the element responsible for the line
and the mean lower-level excitation potential of interlocked lines. We
explain the effect in terms of radiative interlocking with other lines,
as well as the characteristic size of the volume contributing to the
mean intensity.
---------------------------------------------------------
Title: Review of Publications Student Guide to Contemporary Astronomy
Authors: Pasachoff, Jay M.; Kutner, Marc L.; Pasachoff, Naomi
1978JRASC..72R.117P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Review of Publications Contemporary Astronomy
Authors: Pasachoff, Jay M.
1978JRASC..72Q.117P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Infrared Observations of the 1977 Total Solar Eclipse.
Authors: Pasachoff, J. M.; Sanford, M. T., II; Keller, C. F., Jr.
1978BAAS...10..431P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Hopkins Observatory, Williams College, Williamstown,
Massachusetts. Report for the 1976 - 1977 academic year.
Authors: Pasachoff, J. M.
1978BAAS...10..126P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Teacher's guide to university astronomy.
Authors: Pasachoff, J. M.; Kutner, M. L.
1978tgtu.book.....P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: University astronomy
Authors: Pasachoff, J. M.; Kutner, Marc L.
1978unas.book.....P Altcode: 1978QB43.2.P36.....
No abstract at ADS
---------------------------------------------------------
Title: A High Resolution Study of 6-cm Formaldehyde Absorption in
L 134
Authors: Pasachoff, J. M.; Dickman, R. L.; Kutner, M. L.; Tucker, K. D.
1977BAAS....9..591P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Hopkins Observatory, Williamstown, Massachusetts. Observatory
report.
Authors: Pasachoff, J. M.
1977BAAS....9..118P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Student guide to contemporary astronomy.
Authors: Pasachoff, J. M.; Kutner, M. L.; Pasachoff, N.
1977sgtc.book.....P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Contemporary astronomy
Authors: Pasachoff, Jay M.
1977coas.book.....P Altcode: 1977QB45.P29.......
No abstract at ADS
---------------------------------------------------------
Title: Silicon vidicon spectrometry and its infrared capabilities
for solar research
Authors: Pasachoff, J. M.; Muzyka, D. F.; Schierer, J. P., Jr.
1976ApOpt..15.2884P Altcode:
A description is given of the use of a rapid-scanning silicon vidicon
spectrometer at the total solar eclipse of June 30, 1973. The instrument
had been employed to observe the two strong IR coronal emission lines,
which are forbidden lines, of Fe XIII. The ratio of the intensity of
the 1074.7-nm and 1079.8-nm lines is relatively insensitive to coronal
temperature and depends sensitively on the coronal electron density.
---------------------------------------------------------
Title: Fine Structure Variations in High-Spatial-Resolution Solar
Spectra.
Authors: Pasachoff, J. M.; Canfield, R. C.; Stencel, R. E.; Beckers,
J. M.
1976BAAS....8..501P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Infrared coronal lines : (Observations of infrared [iron XIII]
at the 1973 total solar eclipse)
Authors: Pasachoff, J. M.; Muzyka, D. F.
1976VA.....19..341P Altcode:
IT HAS only been recently that vidicon systems have gained sufficient
sensitivity as to allow their use in ground-based infrared studies of
the solar corona. This paper reports on the use of a silicon vidicon
spectrometer for ground-based eclipse studies of infrared coronal
lines. Two forbidden spectral emission lines in the ground state of Fe
XIII in the near infrared at 10,747 Å ( <SUP>3</SUP>P <SUB>1</SUB> →
<SUP>3</SUP>P <SUB>0</SUB>) and 10,798 Å ( <SUP>3</SUP>P <SUB>2</SUB>
→ <SUP>3</SUP>P <SUB>1</SUB>) are the strongest coronal lines in
line-to-continuum ratio accessible to ground-based observers. It has
been shown that the ratio of the intensity of these lines is insensitive
to temperature and provides a good measure of the electron density
in corona since one level is radiatively and the other collisionally
populated. Simultaneous observations of the 10,747 Å and 10,798
Å lines therefore provide a sensitive probe of coronal electron
density. Both coronagraphic and eclipse observations of these lines
have been made but all observations have been severely handicapped
by the fact that the lines lie beyond the effective limit of most
photographic film and on the upper end of the wavelength limit of the
S-1 photocathode of the most commonly employed image tube. At the total
solar eclipse of June 30, 1973 in Kenya, we observed the spectral
region that included the two lines with a Tektronix J20/7J20 rapid
scanning silicon vidicon spectrometer. We scanned the corona in height
from 1.1 to 2.0 R<SUB>⊙</SUB>. We report here on the observations
and their reduction, as well as describe the instrumentation and the
theory of the [Fe XIII] lines.
---------------------------------------------------------
Title: Hopkins Observatory, Williamstown, Massachusetts. Observatory
report.
Authors: Pasachoff, J. M.
1976BAAS....8..111P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book reviews
Authors: Grant athay, R.; Pasachoff, Jay M.
1975SoPh...43..513G Altcode: 1975SoPh...43..513.
No abstract at ADS
---------------------------------------------------------
Title: Abstracts of papers from other journals
Authors: Pasachoff, Jay M.
1975SoPh...43..521P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Infrared Observations of the Solar Corona with a Silicon
Vidicon Spectrometer.
Authors: Pasachoff, J. M.; Muzyka, D. F.
1975BAAS....7..409P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Astrophysical Concepts by Martin Hewitt. Reviewed
Authors: Pasachoff, Jay M.
1975AmJPh..43..197P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Hopkins Observatory, Williams College, Williamstown,
Massachusetts. Observatory report.
Authors: Pasachoff, J. M.
1975BAAS....7...73P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Abstracts of papers from other journals
Authors: Pasachoff, Jay M.
1974SoPh...39..267P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Further observations at the interstellar deuterium frequency.
Authors: Pasachoff, J. M.; Cesarsky, D. A.
1974ApJ...193...65P Altcode:
Two sets of Sgr A observations of neutral deuterium in the direction
of the galactic center are reported. A wider bandwidth was used
in the second set with no significant reduction of overall noise
levels. The line-peak temperature of the merged data from both years
yields an upper limit for the D/H ratio of 0.00035; if the absorption
is the deuterium line, this ratio will be between the above value and
0.00002. These values continue to imply cosmic densities insufficient
to close the universe.
---------------------------------------------------------
Title: Hopkins Observatory, Williams College, Williamstown,
Massachusetts. Observatory report.
Authors: Pasachoff, J. M.
1974BAAS....6...60P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Spatial and Spectral Structure of Chromospheric Lines
Authors: Pasachoff, J. M.; Harris, F. S.; Beckers, J. M.
1974IAUS...56...31P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The Solar Corona
Authors: Pasachoff, Jay M.
1973SciAm.229d..68P Altcode: 1973SciAm.229...68P
No abstract at ADS
---------------------------------------------------------
Title: Abstracts of papers from other journals
Authors: Pasachoff, Jay M.; Uchida, Y.; Vassilyeva, G.; Henoux, J. C.
1973SoPh...30..273P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: 327 MHz observations of the galactic center: Possible detection
of a deuterium absorption line.
Authors: Cesarsky, D. A.; Moffet, A. T.; Pasachoff, J. M.
1973BAAS....5S.284C Altcode:
No abstract at ADS
---------------------------------------------------------
Title: 372-MHz Observations of the Galactic Center: Possible Detection
of a Deuterium Absorption Line
Authors: Cesarsky, Diego A.; Moffet, Alan T.; Pasachoff, Jay M.
1973ApJ...180L...1C Altcode:
We have observed the spectrum of radiation from the galactic center in
the vicinity of the deuterium ground-state hyperfine transition. With
100 hours of observing time the spectrum shows rms fluctuations 7 X
i0- of the on-source power level. An absorption feature at 327.38837 4
0.00001 MHz (corrected to the local standard of rest) has a depth of 2
X i0- of the continuum level. This feature is probably the deuterium
line at VLSR = -3.7 km -1 Subject headings: abundances - hyperfine
structure - interstellar matter
---------------------------------------------------------
Title: Detailed Correlation of Type III Radio Bursts with Hα
Activity. I: Active Region of 22 May 1970
Authors: Kuiper, T. B. H.; Pasachoff, Jay M.
1973SoPh...28..187K Altcode:
We compare observations of type III impulsive radio bursts made
at the Clark Lake Radio Observatory with high-spatial-resolution
cinematographic observations taken at the Big Bear Solar
Observatory. Use of the log-periodic radio interferometer allows us to
localize the radio emission uniquely. This study concentrates on the
particularly active region close to the limb on 22 May 1970. Sixteen
of the 17 groups were associated with some Hα activity, 11 of them
with the start of such activity.
---------------------------------------------------------
Title: Hopkins Observatory, Williams College, Williamstown,
Massachusetts. Observatory report.
Authors: Pasachoff, J. M.
1973BAAS....5..129P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Abstracts of papers from other journals
Authors: Pasachoff, Jay M.
1972SoPh...26..260P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Abstracts of papers from other journals
Authors: De Feiter, L. D.; Pasachoff, Jay M.; Vassilyeva, G.; Gussmann,
E. A.; Vassilyeva, G. J.; Henoux, J. -C.; Uchida, Y.; Namba, O.
1972SoPh...23..501D Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Helium D<SUB>3</SUB> in Stellar Chromospheres.
Authors: Pasachoff, J. M.; Lepler, E. C.
1972BAAS....4Q.235P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Abstracts of papers from other journals
Authors: Pasachoff, Jay M.
1972SoPh...22..503P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Abstracts of papers from other journals
Authors: Henoux, J. -C.; De Feiter, L. D.; Ambroš, P.; Pasachoff,
JAY M.
1972SoPh...22..252H Altcode:
No abstract at ADS
---------------------------------------------------------
Title: R Coronae Borealis.
Authors: Pasachoff, J. M.
1972IAUC.2403....1P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Absolute Intensity Calibrations of Solar K-Line Profiles
Authors: Pasachoff, Jay M.
1971SoPh...19..323P Altcode:
Individual K-line profiles from elements of fine structure on the
surface of the Sun are calibrated absolutely. The continuum calibrations
of Labs and Neckel and of Houtgast and Namba are considered, and the
average K-profile is scaled to that of White and Suemoto.
---------------------------------------------------------
Title: Abstracts of papers from other journals
Authors: Pasachoff, Jay M.; Vassilyeva, G. J.; Henoux, J. -C.; De
Fetter, L. D.
1971SoPh...19..494P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: On K-Line Central Reversals
Authors: Pasachoff, Jay M.; Zirin, Harold
1971SoPh...18...27P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Book review
Authors: Pasachoff, Jay M.
1971SoPh...18..177P Altcode: 1971SoPh...18..177.
No abstract at ADS
---------------------------------------------------------
Title: Book Review: Astronomy and astrophysics. Edited by
S. R. POTTASCH AND J. L. STEINBERG. Springer-Verlag, Berlin,
Price: Institutional subscribers—DM 100 per volume; personal
subscribers—DM 16 per volume
Authors: Pasachoff, Jay M.
1971Icar...14..288P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Abstracts of papers from other journals
Authors: Pasachoff, Jay M.; Henoux, J. -C.; de Feiter, L. D.
1971SoPh...17..277P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Motion picture record of the 7 March 1970 total solar eclipse.
Authors: Pasachoff, J. M.; Menzel, D. H.
1971BAAS....3R.263P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The Calibration of the Wilson-Bappu Effect on the Sun
Authors: Pasachoff, Jay M.
1971ApJ...164..385P Altcode:
A quantitative assessment of the contribution of very asymmetric
spectral profiles from small areas on the solar disk to the mean K4ine
profile for the Sun is now available. Implications for the ilsonBappu
effect are indicated.
---------------------------------------------------------
Title: Abstracts of papers from other journals
Authors: Pasachoff, Jay M.; Stepanyan, N.; Namba, O.
1970SoPh...13..504P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Fine structure in Ca ii on the solar disc
Authors: Pasachoff, Jay M.
1970SoPh...12..202P Altcode:
High-dispersion spectra of the core of the K line of Ca II as seen
at the center of the solar disc have been reduced. Resolution on the
spectra approach 1 arc sec. Line profiles of individual elements are
very asymmetric and often are peaked on only one side of the line
center. Variations of the line profiles and the emission peaks are
discussed. The doubly reversed mean profile of the K line is explained
as a spatial average of individual profiles, and it is suggested that
single peaks may be caused by Doppler-shifted discrete elements in
the chromosphere.
---------------------------------------------------------
Title: Search for New Microwave Spectral Lines from Interstellar
Molecules and Atoms
Authors: Pasachoff, Jay M.; Gottlieb, Carl A.; Snyder, Lewis E.;
Buhl, David; Palmer, Patrick; Zuckerman, B.; Dickinson, Dale F.
1970BAAS....2Q.213P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Abstracts of papers from other journals
Authors: Henoux, J. C.; Pasachoff, Jay M.; Vassilyeva, G. Y.
1970SoPh...11..343H Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Abstracts of papers from other journals
Authors: Uchida, Y.; Gussmann, E. A.; De Feiter, L. D.; Henoux,
J. -C.; Stepanyan, N. N.; Pasachoff, Jay. M.
1970SoPh...11..173U Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Eclipse instrumentation for the solar corona.
Authors: Menzel, D. H.; Pasachoff, J. M.
1970ApOpt...9.2626M Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The Structure of the Solar Transition Zone
Authors: Pasachoff, J. M.
1969cctr.conf..281P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Abstracts of papers from other journals
Authors: Stepanyan, N.; Pasachoff, Jay M.; Ambrož, P.; Vassilyeva,
G.; Henoux, J. -C.; Fokker, A. D.; De Feiter, L. D.; Gussmann, E. A.;
Uchida, Y.; Namba, O.
1969SoPh....8..491S Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Abstracts of papers from other journals
Authors: Pasachoff, Jay M.; AmbroŽ, P.; Namba, O.
1969SoPh....8..248P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Coronal Polarization and Structure at the Total Solar Eclipse
of 22 September 1968
Authors: Schatten, Kenneth H.; Menzel, Donald H.; Pasachoff, Jay M.
1969BAAS....1Q.261S Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Radio Spectra and Related Observations of a Solar Active
Region in July 1968
Authors: Pasachoff, Jay M.; Castelli, John P.
1969BAAS....1S.289P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: K-Line Profiles of Solar Fine Structure
Authors: Pasachoff, Jay M.
1969BAAS....1R.289P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Fine Structure in the Solar Chromosphere.
Authors: Pasachoff, Jay Myron
1969PhDT.........1P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Abstracts of papers from other journals
Authors: Pasachoff, Jay M.; Gussmann, E. A.; Stepanyan, N. N.; de
Feiter, L. D.; Uchida, Yutaka; Švestka, Z.; Vassilyeva, G. J.
1969SoPh....6..155P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Ninety Minutes of Totality!
Authors: Mercer, Robert D.; Pasachoff, Jay M.
1969S&T....37...20M Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Abstracts of papers from other journals
Authors: Pasachoff, Jay M.; Vassilyeva, G. Y.; Henoux, J. -C.;
Stepanyan, N.
1968SoPh....5..588P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Spectral Observations of Spicules at Two Heights in the
Solar Chromosphere
Authors: Pasachoff, Jay M.; Noyes, Robert W.; Beckers, Jacques M.
1968SoPh....5..131P Altcode:
An observational program at the Sacramento Peak Observatory in
1965 provided high-dispersion spectra of the solar chromosphere in
several spectral regions simultaneously. These regions included
various combinations of the spectral lines Hα, Hβ and Hɛ, the
D<SUB>3</SUB>-line of HeI, the infrared triplet of OI, and the H-
and K-lines and the infrared triplet of CaII. With the use of an image
slicer the observations were made simultaneously at two heights in the
solar chromosphere separated by several thousand kilometers. From these
data we draw the following conclusions: Emission of different lines
arises in the same chromospheric features. The intensity ratio of lines
of different elements varies significantly from spicule to spicule. For
the H- and K-lines of ionized calcium, this ratio remains constant,
independent of wavelength throughout the line, overall intensity,
and height in the chromosphere. Two rare-earth lines in the wing of
the H-line show no spicular structure at all.
---------------------------------------------------------
Title: The Interpretation of the Absorption-Line Red-Shifts in the
Solar Spectrum
Authors: Pasachoff, Jay M.; Silk, Joseph I.
1968SoPh....4..474P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: On the Obliteration of Strong Fraunhofer Lines by Electron
Scattering in the Solar Corona
Authors: Menzel, Donald H.; Pasachoff, Jay M.
1968PASP...80..458M Altcode:
No abstract at ADS
---------------------------------------------------------
Title: New Observations of Solar Chromospheric Spicules.
Authors: Beckers, Jaques M.; Noyes, Robert W.; Pasachoff, Jay M.
1966AJ.....71T.155B Altcode:
We observed the spectra of spicules on the solar limb simultaneously at
two heights in the quiescent ebromosphere with the 16-in. coronagraph
and the 12-m Littrow spectrograph at the Sacramento Peak Observatory
during the summer of 1965. Time sequences of simultaneous observations
were obtained, using the following combinations of lines: K, H, HE,
and D3 H, HE, D3, and the 0 1 infrared triplet; H, HE, D3, and the Ca
II infrared triplet; and Hp and HCL. Time intervals between exposures
ranged from 5 to 30 sec, and the height separation was 2000 km. Our
preliminary conclusions follow. (a) A strong correlation exists between
the intensities of the spectra of spicules in HE and D3, while spectra
in H and HE show less correlation. The rare earth line between H and
HE shows no brightness or velocity structure. This suggests that it is
nonspicular in Origin. (b) We see the line-of-sight velocities of some
spicules reverse in direction. This suggests tbat the apparent rising
and subsequent falling seen in HCL on the limb may represent actual
mass motions. Further, most of il~e spicules with large line-of-sight
velocities seem to be moving faster at the higher than at the lower
levels. (c) The profiles of the H and K lines are indeed very broad with
respect to the HCL line, in agreement with Athay. It is unlikely that
these large widths are caused by overlapping spicules. (d) Many spicular
spectra are tilted with respect to the direction of the dispersion. We
believe this to be a real effect, caused by differential motions across
the spicule. (e) The H and K lines are strongly self-reversed at low
levels. We believe the self-reversal to be nonspicular in origin because
it does not share the Doppler shifts of spicules. Microphotometry and
detailed reduction of the data are underway.
