(apart from my
- June, 2021: new version Compendium solar
yellow pages on
- May, 2021: start of a
solar file archive
with 1980s solar line tables, spectrum atlases, model atmospheres,
- April 29, 2021 honoring C. (Kees) de Jager on his 100th
birthday: De zon op Keesdagen / The Sun on Kees
Kees de Jager
100!, size-doubled arXiv
Compendium solar spectrum
- April, 2021: this website is now at
DOT pages: https://robrutten.nl/dot/DOT_home.html.
- March, 2021: Compendium solar spectrum
NIT Calicut solar physics
school. Brief but with optional
page openers for a full course. This second Lingezicht
Astrophysics Report is also livelier than the
- December, 2020: Small-scale solar surface
Summary in “Solar Magnetic Variability and Climate” by C. de
Jager, S. Duhau and A.C.T. Nieuwenhuizen (book
- August, 2020: SolO campfires in SDO
images. This inaugural
webpost of Lingezicht Astrophysics Reports is updated more
frequently than the arXiv
and retains an
on the start of this report series.
- March, 2020:
SDO alignment software
for a covid-postponed
EU SolarNet school.
- August, 2019: solar spectrum formation for irradiancers, a
brief (10 equations only) tutorial expanding my RTSA
in a review published here
- but better view the
because Springer destroyed 100+ citation links
(more Springer nasturtia versus A&A and SoPh praise).
- February, 2018: A year at Sunspot.
Reminiscenses of 1977 - 1978 at the Sacramento Peak Observatory.
- January, 2018: renewed IDL programs
to obtain and co-align
image cutout sequences from the Solar
Dynamics Observatory. See
Also a multi-movie browser and blinker
- May, 2017: The Sun with ALMA: jets and
contrails! at the
72th Nederlandse Astronomenconferentie.
- September, 2016: latex
for clickers opening specific pages
with cited figures, tables, equations, etc.
- November, 2015: new edition of “Introduction
to Astrophysical Radiative Transfer”
by Luc Rouppe van der Voort
- March 1, 2012:
- November 25, 2011: my last day at the nearly
SIU. As farewell I
scanned the courses of M.G.J. Minnaert with which I started my 50
years in Utrecht astronomy.
I also scanned vintage lecture notes by C. Zwaan and his high-school
texts with J. van der Rijst (all in Dutch, under
Cleaning out my desk also made me scan or retrieve ancient courses
“Natuurkunde van zon en sterren”
“Opwekking en transport van straling”
“Introduction to Solar Spectrum Formation”
“Generation and Transport of Radiation”
“Solar and Stellar Magnetism”
- January 2011: end of operation funding for the
Dutch Open Telescope.
It is mothballed since - you are welcome to revive it.
- November 2010: “citeads” latex commands
that generate citations in a pdf file which
link to the corresponding ADS abstract page.
- October 2010: “solabs” solar abstracts
with ADS and ArXiv links for many solar
- September 2010: updates of my
simple IDL manuals.
- August 2010: a speckle demonstration movie
- July 2009: USO School “Solar Magnetism”
held at ASTRON, Dwingeloo, The
- October 2008: photographs from
Nederlandsch-Indisch Java and Sumatra
taken by my father during 1936-1939.
- September 2008: Concluding Remarks
of the 12th European Solar
in a new webpost format for talks.
- April 2007: farewell party at Sonnenborgh
at my mandatory retirement.
- December 2006: final report
which I led during 1998 -
- August 2006: 200-km kayak voyage circuiting
the “Eye of Quebec” asteroid impact.
- July 2003: Epsilon, written in 1997 in memory
of Richard N. Thomas, was finally published.
- November 2001: review of solar
C. (“Kees”) de Jager's 80th birthday.
- November 2000: the housing of Utrecht
- February 2000: Cornelis (“Kees”) Zwaan obituaries for
Solar Physics, Bull. Am. Astron. Soc.,
and JOSO Annual Report 1999. Also a Zwaan
Zwaan's publication list. Zwaan's correspondence and other
science materials are archived at the
- November 1999: popular-astronomy article
on what one did not
see during the August 11 eclipse (in Dutch). What one did not see
were Fraunhofer lines!
The inner corona is the only sunshine-illuminated body in the entire
solar system that does not show them. Walter Grotrian
explained their absence in 1934 as due to enormous Doppler smearing in
Thomson scattering, but without daring to suggest that such large
electron velocities indicate very high temperature. He did that only
much later, after identifying the few coronal emission lines in the
visible as due to highly ionized iron.
During a total solar eclipse you should particularly appreciate that
the corona basks you in pearly sunshine without Fraunhofer lines (and
polarized as well).
- November 1997: photographs of the DOT First Light Ceremony
(featuring Crown Prince Willem-Alexander, Science Minister Jo Ritzen
and many other dignitaries) among other DOT
- August 1997: many thirty-year old astronomer
added to the
- June 1995: start of this website, to offer my course notes
“Radiative transfer in stellar atmospheres”
electronically. I am proud that it started
just when the web came of age, at the same time as the second-best
astronomy site: the Astronomy Picture of the Day
(here is the
very first APOD display). The number-one
astronomy site is the ADS literature server, started in 1994 by