Author name code: penn ADS astronomy entries on 2022-09-14 author:"Penn, Matthew" ------------------------------------------------------------------------ Title: SEARCH: SEgmentation of polAR Coronal Holes Authors: Tiwari, Ajay Kumar; Tremblay, Benoit; Hu, Andong; Wolniewicz, Linnea M.; Kirk, Michael; Guidoni, Silvina; Smith, Brent; Penn, Matthew; Samanta, Tanmoy Bibcode: 2021csss.confE.211T Altcode: The identification of solar coronal holes (CHs) observed in Extreme Ultraviolet (EUV) intensity images of the Sun is key in improving our understanding of their association with solar magnetic fields and heliophysics. In particular, CHs at the poles of the Sun are a notorious source of fast solar wind and thus warrant further study, most notably in the context of space-weather forecasting. This has consequently led to the development of various segmentation methods for their identification, including supervised machine learning. We introduce the SEARCH project to combine EUV data from the three vantage points (e.g., STEREO-A, STEREO-B, and SoHO) during the 2010-2014 epoch to produce synchronic maps and apply unsupervised learning methods including clustering and convolutional neural networks for the segmentation of CHs. SEARCH segmentation maps provide a venue to explore the relationship between CH pole areas, geomagnetic activity, and the magnetic activity cycle (dynamo process) of the Sun and Sun-like stars. Finally, in addition to CHs, the unsupervised learning methods we tested identified features consistent with active regions. Title: Acceleration of Coronal Mass Ejection Plasma in the Low Corona as Measured by the Citizen CATE Experiment Authors: Penn, Matthew J.; Baer, Robert; Walter, Donald; Pierce, Michael; Gelderman, Richard; Ursache, Andrei; Elmore, David; Mitchell, Adrianna; Kovac, Sarah; Hare, Honor; McKay, Myles; Jensen, Logan; Watson, Zachary; Conley, Mike; Powers, Lynn; Lazarova, Marianna; Wright, Joseph; Young, David; Isberner, Fred; Hart, C. Alexandra; Sheeley, N. R., Jr.; Penn, Debbie; Allen-Penn, Kate; Alder, Bruce; Alder, Ryan; Hall-Conley, Geri; Gerdes, David; Weber, Katherine; Johnson, Jeffrey; Matzek, Gerald; Somes, Steven; Sobnosky, Rob; McGowen, Robert; Meo, Michael; Proctor, Damani; Wessinger, Charlie; Schilling, Jeannine; Kerr, Jay; Beltzer-Sweeney, Alexander; Falatoun, Alex; Higgins, David; Boyce, Grady; Hettick, Jared; Blanco, Philip; Dixon, Scott; Ardebilianfard, Sepehr; Boyce, Pat; Lighthill, Richard; Lighthill, Denese; Anderson, David; Anderson, Mine; Schad, Thomas; Smith, Sonna; Jensen, Declan; Allen, Anthony; Smith, Donavan; Brandon, Gage; Earp, Joe; Earp, Jane; Blair, Bob; Claver, Chuck F.; Claver, Jennifer A.; Claver, Ryan H.; Hoops, Danielle; Rivera, Esteban; Gibson, Llanee; Hiner, Martin; Lann, Rein; Miller, Shaedyn; Briggs, Burton; Davis, Karan; Jackson, Brian; Kautzsch, Kaleb; Sandidge, Wesley; Lucas, Russell; Gregg, Duane; Kamenetzky, Julia; Rivera, Tiffany; Shaw, Joe; Scherrer, Bryan; Sandbak, Dylan; McFate, Richard; Harris, Wilson; Brasier, Zachery; McNeil, Stephen; Jensen, Jack; Jensen, Makai; Moore, Mason; Temple, Alexandria; Vanderhorst, Thomas; Kautz, Richard; Bellorado, Orion; Jenkins, LaVor R.; Pantuso, Corey; Carey, Marley; Byrnes, Josh; Scholtens, Kyle; Web, Julian; Baker, Brain; Barngrover, Katie; Hathaway, Drew; Smith, Kallen; Chandler, Kellyn; Hinkle, Lydia; Chandler, Ione; Gisler, Galen; Benner, Jack; Mas, Madison; Rogers, Maya; Moore, Prescott; Pelofske, Elijah; Gulley, Stephen; Short, Beth; Crooker, Isabel; Hammock, Jennifer; Cardenas, Katsina; Cardenas, Kateri; Wellman, Jennifer; Roy, Mark; Meyer, Joe; Brough, Jalynne; Brough, Kameron; Nelson, Tim; Nelson, Zack; Russell, Caleb; Bautz, Theresa; Weitzel, Eric; Team; Wistisen, Michele; Aagard, Shae; Whipps, Zachary; Neuroth, Logan; Poste, Dawson; Worthen, Connor; Gosain, Sanjay; Steward, Mark; Gosain, Vanshita; Gosain, Ruchi; Jorgensen, Janet; Doucette, Eleanor; Doucette, Reba; Iwen, Elliott; Cochran, Alexus; Stith, James; Scribner, Doug; Kenney, Austen; Pisciotti, Kolby; Pease, Irene; Cynamon, Samuel; Cynamon, Charles; Cynamon, Dawn; Tolbert, Bart; Dupree, Jean A.; Weremeichik, Jeremy; Pindell, Nathan; Stives, Kristen; Simacek, Thomas K.; Simacek, Yolanta G.; Simacek, Anne L.; Boeck, Wayne; Boeck, Andreea; Ryan, Austin; Wierzorec, Gabriel; Klebe, Dimitri; Costanza, Bryan; Cerny, Arnie; Schmale, Trevor; Hoffman, Tessa; Streeter, Sam; Erickson, Jack; McClellan, Michele; Erickson, Ella; Brettell, Brynn; Shoffner, Savannah; McClellan, Emilie; VanVoorhis, Julie; Bramhall, Cole; Stelly, Daniel; Bee, Bentley; Acevedo, Bruno; Kroeger, Madison; Trumpenski, Ben; Sump, Nolan; Brook, Liam; Ernzen, Jagert; Lewis, Jessica; Maderak, Ryan; Kennedy, Charles; Dembinski, David; Wright, Rita; Foster, Michael; Ahmadbasir, Mohammad; Laycox, Monty; Foster, James; Orr, Ethan; Staab, Ashley; Speck, Angela; Baldridge, Sean; Kegley, Lucy; Bavlnka, Jordan; Ballew, Thomas; Callen, Bruce; Ojakangas, Gregory; Bremer, Mark; Angliongto, Maryanne; Redecker, Mark; Bremer, Chris; Hill, Peggy; Rodgers, Michael; Duncan, Jordan; Fincher, Sam; Nielsen, Ben; Hasler, Samantha; Shivelbine, Taylor; Howard, Tyler; Midden, Chris; Patrick, Sean; Glenn, Kerry; Mandrell, Chris; Dawson, Kyle; Cortez, Margaret; Levsky, Alyssa; Gallaba, Dinuka; Perrone, Mason; Taylor, Jasmyn; Yanamandra-Fisher, Padma A.; Harper, Howard; Adams, Lindsay; Springer, Michaela; Menard, BillyJoe; Boggs, Dylan; Lynch, Caitlin; Watson, Jacob; York, Andi; Matthews, David; Brown, Kiley; Garrison, Dylan; Mangin, Jonathan; Mangin, Isaac; Birriel, Jennifer; Birriel, Ignacio; Yess, Capp; Anderson, Jesse; Caudill, Ethan; Smith, Allyn; Buckner, Spencer; Longhurst, Russ; Fagan, Ben; Nations, Christian; DiMatties, Jeffrey; Thompson, Patricia; Garrison, David; Garrison, Thomas; Garrison, William; Kidd, Mary; Baker, Maria; Ledford, Mary-Beth; Winebarger, Amy; Freed, Michael; Church, Morgyn; Dickens, Jim; Anderson, Bob; Smith, Ned; Dorsey, Lynne; Justice, Doug; Zavala, Daniel; Stockbridge, Zach; Brittain, Sean; Jensen, Stanley; Leiendecker, Harrison; Thompson, Erin; Deady, Michelle; Quinn-Hughes, Kelly; Slimmer, David; Granger, Valerie; LaRoche, Michael; Hill LaRoche, Serena; Manspeaker, Rachel; Nguyen, Peter; Smith, Daniel; Payne, Jim; Zissett, Jerry; Roberts, Arianna M.; Roberts, Gabrielle W.; Roberts, Harrison; Riddle, Amy; Ursache, Corina; Ursache, Elena Bibcode: 2020PASP..132a4201P Altcode: The citizen Continental-America Telescopic Eclipse (CATE) Experiment was a new type of citizen science experiment designed to capture a time sequence of white-light coronal observations during totality from 17:16 to 18:48 UT on 2017 August 21. Using identical instruments the CATE group imaged the inner corona from 1 to 2.1 RSun with 1.″43 pixels at a cadence of 2.1 s. A slow coronal mass ejection (CME) started on the SW limb of the Sun before the total eclipse began. An analysis of CATE data from 17:22 to 17:39 UT maps the spatial distribution of coronal flow velocities from about 1.2 to 2.1 RSun, and shows the CME material accelerates from about 0 to 200 km s-1 across this part of the corona. This CME is observed by LASCO C2 at 3.1-13 RSun with a constant speed of 254 km s-1. The CATE and LASCO observations are not fit by either constant acceleration nor spatially uniform velocity change, and so the CME acceleration mechanism must produce variable acceleration in this region of the corona. Title: First results from the Citizen CATE Experiment from August 2017 Authors: Penn, Matthew; Citizen CATE Experiment 2017 Team Bibcode: 2018AAS...23122005P Altcode: The Citizen Continental-America Telescopic Eclipse Experiment deployed 68 identical telescope/detector systems across the path of totality for the August 2017 solar eclipse. The sites were located from Oregon to South Carolina, and while at any one site the solar corona was observed for just 2 minutes, the combined data set reveals evolution of the corona for 93 minutes of time. CATE aims to measure the acceleration of the fast solar wind in polar plumes, which is currently unknown as the inner solar corona is not observed from space and difficult to observe at high signal to noise from the ground. With radial velocities ranging from 1 to 100 km/s, density enhancements in the wind in the polar plumes should be observed to move across the CATE field of view in about 1 hour.On 21 Aug 2017, the CATE network had fantastic luck, collecting data from more than 56 of the 68 sites, and excellent data was collected at the first and last sites, maximizing the time coverage. Several of the volunteers from 27 universities, 22 high schools and 19 amateur astronomers uploaded one high-dynamic range image on eclipse day and an initial movie of the coronal evolution has been made (https://citizencate.org ). Polar plumes are observed in the CATE data to the edge of the field above both north and south polar coronal holes. Slow evolution of low-lying coronal loops is seen, and large-scale motions are visible in a coronal streamer on the south-east solar limb. An ejection event is observed in the southern coronal hole, but with just 1% of the data analyzed so far, the signal to noise ratio is currently not sufficient to track steady solar wind flows.CATE was funded with a collaboration of federal, corporate and private groups. CATE training was funded by NASA, and CATE equipment was funded by Daystar, Mathworks, Celestron, colorMaker, NSF and a dozen smaller donors. The funding was organized so that all 68 CATE groups are keeping their equipment, and CATE is now seeking other types of citizen science projects in astronomy. Please bring your project ideas to the talk! Title: The Citizen CATE Experiment: Techniques to Determine Totality Coverage and Clouded Data Removal. Authors: McKay, Myles A.; Ursache, Andrei; Penn, Matthew; Citizen CATE Experiment 2017 Team Bibcode: 2018AAS...23124206M Altcode: August 21, 2017, the Citizen Continental-America Telescopic Eclipse(CATE) Experiment observed the 2017 total solar eclipse using a network of 68 identical telescopes and camera systems along the path of totality. The result from the observation was over 90% of all sites collected totality data on the day of the eclipse. Since the volunteers had to remove the solar filter manually, there is an uncertainty between the time of totality and data acquired during totality. Some sites also experienced cloudy weather which obscured the eclipse in some of the exposures but had small breaks in the clouds during the observation, collecting clear totality data. Before we can process and analyze the eclipse data, we must carefully determine which frames cover the time of totality for each site and remove exposures with clouds blocking the FOV. In this poster, we will discuss the techniques we used to determine the extent of totality from each location using the logged GPS data and the removal of totality exposure with clouds. 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 Bibcode: 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: Polarization Observations of the Total Solar Eclipse of August 21, 2017 Authors: Burkepile, J.; Boll, A.; Casini, R.; de Toma, G.; Elmore, D. F.; Gibson, K. L.; Judge, P. G.; Mitchell, A. M.; Penn, M.; Sewell, S. D.; Tomczyk, S.; Yanamandra-Fisher, P. A. Bibcode: 2017AGUFMSH13B2477B Altcode: A total solar eclipse offers ideal sky conditions for viewing the solar corona. Light from the corona is composed of three components: the E-corona, made up of spectral emission lines produced by ionized elements in the corona; the K-corona, produced by photospheric light that is Thomson scattered by coronal electrons; and the F-corona, produced by sunlight scattered from dust particles in the near Sun environment and in interplanetary space. Polarized white light observations of the corona provide a way of isolating the K-corona to determine its structure, brightness, and density. This work focuses on broadband white light polarization observations of the corona during the upcoming solar eclipse from three different instruments. We compare coronal polarization brightness observations of the August 21, 2017 total solar eclipse from the NCAR/High Altitude Observatory (HAO) Rosetta Stone experiment using the 4-D Technology PolarCam camera with the two Citizen PACA_CATE17Pol telescopes that will acquire linear polarization observations of the eclipse and the NCAR/HAO K-Cor white light coronagraph observations from the Mauna Loa Solar Observatory in Hawaii. This comparison includes a discussion of the cross-calibration of the different instruments and reports the results of the coronal polarization brightness and electron density of the corona. These observations will be compared with results from previous coronal measurements taken at different phases of the solar cycle. In addition, we report on the performance of the three different polarimeters. The 4-D PolarCam uses a linear polarizer array, PACA_CATE17Pol uses a nematic liquid crystal retarder in a single beam configuration and K-Cor uses a pair of ferroelectric liquid crystal retarders in a dual-beam configuration. The use of the 4-D PolarCam camera in the Rosetta Stone experiment is to demonstrate the technology for acquiring high cadence polarization measurements. The Rosetta Stone experiment is funded through the NASA award NNH16ZDA001N-ISE. The Citizen Science approach to measuring the polarized solar corona during the eclipse is funded through NASA award NNX17AH76G. The NCAR Mauna Loa Solar Observatory is funded by the National Science Foundation. Title: First results from the Citizen CATE Experiment 2017 Authors: Penn, M. J. Bibcode: 2017AGUFMSH24A..03P Altcode: The Citizen Continental-America Telescopic Eclipse (CATE) Experiment will monitor the corona using a network of 68 identical telescopes positioned along the path of totality on 21 August 2017. The individual high quality images taken during the 2 minutes of totality at each site will be combined to create a uninterrupted 93 minute sequence of the inner solar corona. CATE data will image the inner corona in white light using wavelengths between 480nm and 680nm. With 1.5 arcsec pixels, the transverse velocity sensitivity will be roughly from 1-150 km/s. Sites will collect a sequence of 8 exposures from 0.4 msec up to 1.3 sec duration, and these exposures will be used to produce one high-dynamic range image every 2.1 seconds. The expected signal to noise ratio in the data should allow brightness fluctuations of about 5% to be detected. The initial science goal is to measure the solar wind velocity and acceleration in polar plumes as the plasma accelerates from 1 to 100 km/s in the CATE field-of-view. Title: Critical Infrared Science with the Daniel K. Inouye Solar Telescope Authors: Schad, Thomas A.; Fehlmann, Andre; Jaeggli, Sarah A.; Kuhn, Jeffrey Richard; Lin, Haosheng; Penn, Matthew J.; Rimmele, Thomas R.; Woeger, Friedrich Bibcode: 2017SPD....4811703S Altcode: Critical science planning for early operations of the Daniel K. Inouye Solar Telescope is underway. With its large aperture, all-reflective telescope design, and advanced instrumentation, DKIST provides unprecedented access to the important infrared (IR) solar spectrum between 1 and 5 microns. Breakthrough IR capabilities in coronal polarimetry will sense the coronal magnetic field routinely for the first time. The increased Zeeman resolution near the photospheric opacity minimum will provide our deepest and most sensitive measurement of quiet sun and active region magnetic fields to date. High-sensitivity He I triplet polarimetry will dynamically probe the chromospheric magnetic field in fibrils, spicules, and filaments, while observations of molecular CO transitions will characterize the coolest regions of the solar atmosphere. When combined with the longer timescales of good atmospheric seeing compared with the visible, DKIST infrared diagnostics are expected to be mainstays of solar physics in the DKIST era. This paper will summarize the critical science areas addressed by DKIST infrared instrumentation and invite the community to further contribute to critical infrared science planning. Title: The thermal infrared continuum in solar flares Authors: Fletcher, Lyndsay; Simoes, Paulo; Kerr, Graham Stewart; Hudson, Hugh S.; Gimenez de Castro, C. Guillermo; Penn, Matthew J. Bibcode: 2017SPD....4810821F Altcode: Observations of the Sun with the Atacama Large Millimeter Array have now started, and the thermal infrared will regularly be accessible from the NSF’s Daniel K. Inouye Solar Telescope. Motivated by the prospect of these new observations, and by recent flare detections in the mid infrared, we set out here to model and understand the source of the infrared continuum in flares, and to explore its diagnostic capability for the physical conditions in the flare atmosphere. We use the 1D radiation hydrodynamics code RADYN to calculate mid-infrared continuum emission from model atmospheres undergoing sudden deposition of energy by non-thermal electrons. We identify and characterise the main continuum thermal emission processes relevant to flare intensity enhancement in the mid- to far-infrared (2-200 micron) spectral range as free-free emission on neutrals and ions. We find that the infrared intensity evolution tracks the energy input to within a second, albeit with a lingering intensity enhancement, and provides a very direct indication of the evolution of the atmospheric ionization. The prediction of highly impulsive emission means that, on these timescales, the atmospheric hydrodynamics need not be considered in analysing the mid-IR signatures. Title: Multi-site Observations of the March 2016 Total Solar Eclipse: Calibration of Images to Simulate Continuous Monitoring Authors: Bosh, Robert; Penn, Matthew J.; McKay, Myles; Baer, Robert; Garrison, David; Gelderman, Richard; Hare, Honor; Isberner, Fred; Jensen, Logan; Kovac, Sarah; Mitchell, Adriana; Pierce, Michael; Thompson, Patricia; Ursache, Andrei; Varsik, John R.; Walter, Donald K.; Watson, Zachary; Young, David; Citizen Cate Team Bibcode: 2017AAS...22942401B Altcode: During the total solar eclipse of March 9, 2016, five teams of astronomers participating in the Citizen Continental America Telescopic Eclipse (CATE) experiment, traveled to different locations in Indonesia to observe the eclipse. Data was acquired to continuously monitor the progression of features in the inner solar corona: a region of the solar atmosphere where time evolution is not well understood. Image data from the eclipse consisted of sets of 7 exposure times 0.4, 1.3, 4, 13, 40, 130, and 400 milliseconds which are used to create a high dynamic range composite image. Eclipse data from these sites were then processed and calibrated using sets of dark and flat images. Further data processing included the compilation of exposures into high dynamic range images and were subsequently spatially filtered. Using these processing techniques, data from each site was aligned and compiled as frames in videos of the eclipse, each consisting of over 140 frames with the goal of being combined. Lessons learned from the data obtained in the observations of the 2016 total solar eclipse are being used to improve the procedure which will be used in the CATE experiment during the North American 2017 total solar eclipse. Title: Instrumentation for the Citizen CATE Experiment: Faroe Islands and Indonesia Authors: Penn, M. J.; Baer, R.; Bosh, R.; Garrison, D.; Gelderman, R.; Hare, H.; Isberner, F.; Jensen, L.; Kovac, S.; McKay, M.; Mitchell, A.; Pierce, M.; Thompson, P.; Ursache, A.; Varsik, J.; Walter, D.; Watson, Z.; Young, D.; Citizen CATE Team Bibcode: 2017PASP..129a5005P Altcode: 2016arXiv160900035P The inner regions of the solar corona from 1-2.5 Rsun are poorly sampled both from the ground and space telescopes. A solar eclipse reduces the sky scattered background intensity by a factor of about 10,000 and opens a window to view this region directly. The goal of the Citizen Continental-America Telescopic Eclipse (CATE) Experiment is to take a 90-minute time sequence of calibrated white-light images of this coronal region using 60 identical telescopes spread from Oregon to South Carolina during the 2017 August 21 total solar eclipse. Observations that can address questions of coronal dynamics in this region can be collected with rather modest telescope equipment, but the large dynamic range of the coronal brightness requires careful camera control. The instruments used for test runs on the Faroe Islands in 2015 and at five sites in Indonesia in 2016 are described. Intensity calibration of the coronal images is done and compared with previous eclipse measurements from November & Koutchmy and Bazin et al. The change of coronal brightness with distance from the Sun seen in the 2016 eclipse agrees with observations from the 1991 eclipse, but differ substantially from the 2010 eclipse. The 2015 observations agree with 2016 and 1991 solar radii near the Sun, but are fainter at larger distances. Problems encountered during these test runs are discussed as well the solutions which will be implemented for the 2017 eclipse experiment. Title: Vector Magnetic Field Measurements along a Cooled Stereo-imaged Coronal Loop Authors: Schad, T. A.; Penn, M. J.; Lin, H.; Judge, P. G. Bibcode: 2016ApJ...833....5S Altcode: 2016arXiv161005332S The variation of the vector magnetic field along structures in the solar corona remains unmeasured. Using a unique combination of spectropolarimetry and stereoscopy, we infer and compare the vector magnetic field structure and three-dimensional morphology of an individuated coronal loop structure undergoing a thermal instability. We analyze spectropolarimetric data of the He I λ10830 triplet (1s2s{}3{S}1-1s2p{}3{P}{2,1,0}) obtained at the Dunn Solar Telescope with the Facility Infrared Spectropolarimeter on 2011 September 19. Cool coronal loops are identified by their prominent drainage signatures in the He I data (redshifts up to 185 km s-1). Extinction of EUV background radiation along these loops is observed by both the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory and the Extreme Ultraviolet Imager on board spacecraft A of the Solar Terrestrial Relations Observatory, and is used to stereoscopically triangulate the loop geometry up to heights of 70 Mm (0.1R Sun) above the solar surface. The He I polarized spectra along this loop exhibit signatures indicative of atomic-level polarization, as well as magnetic signatures through the Hanle and Zeeman effects. Spectropolarimetric inversions indicate that the magnetic field is generally oriented along the coronal loop axis, and provide the height dependence of the magnetic field intensity. The technique we demonstrate is a powerful one that may help better understand the thermodynamics of coronal fine-structure magnetism. Title: Spectropolarimetry of Atomic and Molecular Lines near 4135 nm Authors: Penn, Matthew James; Uitenbroek, Han; Clark, Alan; Coulter, Roy; Goode, Phil; Cao, Wenda Bibcode: 2016SoPh..291.2243P Altcode: 2015arXiv151204451P; 2016SoPh..tmp..142P New spatially scanned spectropolarimetry sunspot observations are made of photospheric atomic and molecular absorption lines near 4135 nm. The relative splittings among several atomic lines are measured and shown to agree with values calculated with configuration interaction and intermediate coupling. Large splitting is seen in a line identified with Fe I at 4137 nm, showing multiple Stokes V components and an unusual linear polarization. This line will be a sensitive probe of quiet-Sun magnetic fields, with a magnetic sensitivity of 2.5 times higher than that of the well-known 1565 nm Fe I line. Title: Coronal Science from the Citizen CATE Experiment Authors: Penn, Matthew J.; Pierce, Mike; Jensen, Logan; Baer, Bob; Kovac, Sarah; Gelderman, Richard; Hare, Honor; Walter, Don; McKay, Myles Bibcode: 2016shin.confE.154P Altcode: The 2017 August total solar eclipse path crosses the USA from Oregon to South Carolina, and the path is accessible at countless points. At any single location totality lasts about 2 minutes, but the lunar shadow takes 90 minutes to traverse the continent. With a collection of 60 identical telescopes at 50 mile intervals, the Citizen CATE Experiment will collect white images of the solar corona from 1 to 2 solar radii with 1500km resolution for a period of 90 minutes.

This unique data set probes spatial and temporal domains impossible to observe from the ground or space. Assuming a typical solar minimum corona, our science will focus on the dynamics of polar plumes and the prominence-coronal interface. Polar plumes are thought to host periodic or quasi-periodic density enhancements moving radially outward; current work suggests 3-15% density enhancements moving at 60-210 km/sec with periods from 7-15 minutes. Rayleigh-Taylor plasma instabilities observed in prominences at 2250km size scales with upward velocities of 20 km/sec are thought to form larger dynamic structures in the hot coronal plasma after leaving the prominence. The CATE data, with transverse velocity sensitivities of 1 to 145 km/sec during the 90 minute duration will be used to tightly constrain both of these solar phenomena. If the corona shows eruptive activity during the eclipse, the CATE data can provide unique and stunning measurements of CMEs, active region loop oscillations or even coronal inflows.

We will review results from CATE tests from the Faroe Islands in 2015 and from Indonesia in 2016, and provide a current status of CATE for the 2017 eclipse. The education and public outreach impact of this event, which may be directly viewed by 20 million and seen on TV and internet by more than 100 million will also be discussed. Title: Student artistry sparks eclipse excitement on Maui: NSO/DKIST EPO for the 2016 Partial Solar Eclipse Authors: Schad, Thomas A.; Penn, Matthew J.; Armstrong, James Bibcode: 2016SPD....47.0501S Altcode: Local creativity and artistry is a powerful resource that enhances education programs and helps us generate excitement for science within our communities. In celebration of the 2016 Solar Eclipse, the National Solar Observatory (NSO) and its Daniel K Inouye Solar Telescope (DKIST) project were pleased to engage with students across Maui County, Hawai`i, via the 2016 Maui Eclipse Art Contest. With the help of the Maui Economic Development Board and the University of Hawai'is Institute for Astronomy, we solicited art entries from all K-12 schools in Maui County approximately 6 months prior to the eclipse. Along with divisional prizes, a grand prize was selected by a panel of local judges, which was subsequently printed on 25,000 solar eclipse viewing glasses and distributed to all Maui students. We found that the impact of a locally-sourced glasses design cannot be understated. Overall, the success of this program relied upon reaching out to individual teachers, supplying educational flyers to all schools, and visiting classrooms. On the day of the eclipse, all of the art entries were prominently displayed during a community eclipse viewing event at Kalama Beach Park in Kihei, HI, that was co-hosted by NSO and the Maui Science Center. This eclipse art contest was integral to making local connections to help promote science education on Maui, and we suggest that it could be adapted to the solar community's EPO activities for the upcoming 2017 Great American Solar Eclipse. Title: Cross-Calibrating Sunspot Magnetic Field Strength Measurements from the McMath-Pierce Solar Telescope and the Dunn Solar Telescope Authors: Watson, Fraser T.; Beck, Christian; Penn, Matthew J.; Tritschler, Alexandra; Pillet, Valentín Martinez; Livingston, William C. Bibcode: 2015SoPh..290.3267W Altcode: 2015arXiv151107315W; 2015SoPh..tmp..158W In this article we describe a recent effort to cross-calibrate data from an infrared detector at the McMath-Pierce Solar Telescope and the Facility InfraRed Spectropolarimeter (FIRS) at the Dunn Solar Telescope. A synoptic observation program at the McMath-Pierce has measured umbral magnetic field strengths since 1998, and this data set has recently been compared with umbral magnetic field observations from SOHO/MDI and SDO/HMI. To further improve on the data from McMath-Pierce, we compared the data with measurements taken at the Dunn Solar Telescope with far greater spectral resolution than has been possible with space instrumentation. To minimise potential disruption to the study, concurrent umbral measurements were made so that the relationship between the two datasets can be most accurately characterised. We find that there is a strong agreement between the umbral magnetic field strengths recorded by each instrument, and we reduced the FIRS data in two different ways to successfully test this correlation further. Title: He I Vector Magnetic Field Maps of a Sunspot and Its Superpenumbral Fine-Structure Authors: Schad, T. A.; Penn, M. J.; Lin, H.; Tritschler, A. Bibcode: 2015SoPh..290.1607S Altcode: 2015arXiv150505567S; 2015SoPh..tmp...60S Advanced inversions of high-resolution spectropolarimetric observations of the He I triplet at 1083 nm are used to generate unique maps of the chromospheric magnetic field vector across a sunspot and its superpenumbral canopy. The observations were acquired by the Facility Infrared Spectropolarimeter (FIRS) at the Dunn Solar Telescope (DST) on 29 January 2012. Multiple atmospheric models are employed in the inversions because superpenumbral Stokes profiles are dominated by atomic-level polarization, while sunspot profiles are Zeeman-dominated, but also exhibit signatures that might be induced by symmetry-breaking effects of the radiation field incident on the chromospheric material. We derive the equilibrium magnetic structure of a sunspot in the chromosphere and furthermore show that the superpenumbral magnetic field does not appear to be finely structured, unlike the observed intensity structure. This suggests that fibrils are not concentrations of magnetic flux, but are instead distinguished by individualized thermalization. We also directly compare our inverted values with a current-free extrapolation of the chromospheric field. With improved measurements in the future, the average shear angle between the inferred magnetic field and the potential field may offer a means to quantify the non-potentiality of the chromospheric magnetic field to study the onset of explosive solar phenomena. Title: Citizen CATE Experiment: Prototype Testing and Plans Authors: Penn, Matthew; Baer, Bob; Isberner, Fred Bibcode: 2015SASS...34...63P Altcode: An off-the-shelf small refracting telescope and digital imaging system was purchased and tested for application to a citizen science experiment to be run during the 2017 total solar eclipse. Ease of set-up, imaging ability, and sensitivity tests were done, and then the telescope was shipped to take data at the 2015 total solar eclipse from the Faroe Islands. Details of the equipment, results from the tests, and plans for future eclipses are discussed. Title: New Vector Spectropolarimetry of Sunspots near 4000nm Authors: Penn, Matthew J.; Coulter, Roy; Goode, Philip R. Bibcode: 2014AAS...22411201P Altcode: Magnetic sensitivity of spectral lines increases as the product of the wavelength and the Lande g-factor. While the most magnetically sensitive spectral line known is the Mg I 12318nm line, and observations are often made near 1600nm, little work has been done using solar spectral lines near 4000nmWe report on new solar spectropolarimetric observations at these wavelengths, made at the NSO McMath-Pierce facility with the NAC and at the NJIT New Solar Telescope using CYRA. Several photospheric absorption lines have been used to map a sunspot magnetic field, and molecular line Zeeman splitting has also been observed. Several "negative-g" molecular lines are seen, and an atomic line shows unusual profiles. Title: A Spectro-polarimetric Analysis of Sunspot Umbrae Authors: Watson, Fraser; Tritschler, Alexandra; Penn, Matthew J.; Beck, Christian; Livingston, William; Martinez Pillet, Valentin Bibcode: 2014AAS...22411202W Altcode: The recent quiet solar cycle has invited new questions as to the nature of the solar magnetic field and how it changes over time. To investigate this, we use the National Solar Observatory’s McMath-Pierce Solar Telescope Facility (McMP) and Dunn Solar Telescope (DST) to compare measurements of sunspots from five active regions observed in 2013. Both BABO at the McMP and FIRS at the DST were used to provide spectra of the Fe 1564.8nm line, which is affected by the presence of magnetic fields. The magnetic field is derived from Zeeman splitting in Stokes-I by BABO, and by inversion of the Stokes parameters from FIRS data allowing for comparisons of sunspot properties between the two instruments.. We present the first results from this study including the magnetic fields in sunspot umbrae from five active regions measured simultaneously by BABO and FIRS. Title: A Multi-instrument Analysis of Sunspot Umbrae Authors: Watson, F. T.; Penn, M. J.; Livingston, W. Bibcode: 2014ApJ...787...22W Altcode: 2015arXiv151107300W The recent solar minimum and rise phase of solar cycle 24 have been unlike any period since the early 1900s. This article examines some of the properties of sunspot umbrae over the last 17 yr with three different instruments on the ground and in space: MDI, HMI and BABO. The distribution of magnetic fields and their evolution over time is shown and reveals that the field distribution in cycle 24 is fundamentally different from that in cycle 23. The annual average umbral magnetic field is then examined for the 17 yr observation period and shows a small decrease of 375 G in sunspot magnetic fields over the period 1996-2013, but the mean intensity of sunspot umbrae does not vary significantly over this time. A possible issue with sample sizes in a previous study is then explored to explain disagreements in data from two of the source instruments. All three instruments show that the relationship between umbral magnetic fields and umbral intensity agrees with past studies in that the umbral intensity decreases as the field strength increases. This apparent contradiction can be explained by the range of magnetic field values measured for a given umbral intensity being larger than the measured 375 G change in umbral field strength over time. Title: Infrared Solar Physics Authors: Penn, Matthew J. Bibcode: 2014LRSP...11....2P Altcode: The infrared solar spectrum contains a wealth of physical data about our Sun, and is explored using modern detectors and technology with new ground-based solar telescopes. The scientific motivation behind exploring these wavelengths is presented, along with a brief look at the rich history of observations here. Several avenues of solar physics research exploiting and benefiting from observations at infrared wavelengths from roughly 1000 nm to 12 400 nm are discussed, and the instrument and detector technology driving this research is briefly summarized. Finally, goals for future work at infrared wavelengths are presented in conjunction with ground and space-based observations. Title: A Systematic Look At Sunspots From Space: 1996 - 2013 Authors: Watson, Fraser; Penn, M. J.; Livingston, W. Bibcode: 2013SPD....4420401W Altcode: Space based measurements of sunspots are still relatively new when compared with the long visual record that is available from ground based observatories, but they can provide many advantages that ground based measurements cannot. Sunspots are automatically detected from SOHO/MDI and SDO/HMI continuum images using the Sunspot Tracking And Recognition Algorithm (STARA). A self consistent sunspot catalogue is created using the same criteria for detecting sunspots throughout time, eliminating effects seen by ground observatories such as changing observers or the effect of an observers eyesight as they age. This catalogue is then analysed to determine how sunspots evolve and what their population is in a number of physical parameters, which is of great importance for simulations of magnetic flux emergence and the solar dynamo. In particular, the change in sunspot parameters between solar cycles 23 and 24 is of great interest as the cycles appear vastly different in activity, and sunspots are a primary indicator of the activity of the Sun. The catalogue is also freely available for use by the community. Title: Coronal science with the ATST Authors: Penn, Matthew J. Bibcode: 2013SPD....4440101P Altcode: The ATST project recently began construction on Haleakala, Maui. When combined with the dark daytime sky conditions at the site, the low scattered light primary mirror should allow ATST to make coronal observations at infrared wavelengths. These data will address several coronal science topics included in the ATST Science Requirements Document. I will review the early work done by the ATST Coronal Science Working Group, including these coronal science use cases and the expected background-limited measurement errors. In summary, the Working Group found that given good sky conditions the 1-sigma measurement errors in a 40 millionths brightness corona were 0.04 millionths for intensity, 9 x 10^4 cm^-3 for electron density, 37 m s^-1 for velocity and 33 Gauss for the magnetic field as measured in a 1 arcsecond square pixel with a 1 second exposure using the infrared coronal emission lines at 1075nm. These measurement errors increase as the telescope or sky backgrounds increase. Finally I will update these error estimates from the latest telescope models, and discuss recent coronal science topics. 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. Bibcode: 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: He I Vector Magnetometry of Field-aligned Superpenumbral Fibrils Authors: Schad, T. A.; Penn, M. J.; Lin, H. Bibcode: 2013ApJ...768..111S Altcode: 2013arXiv1303.4463S Atomic-level polarization and Zeeman effect diagnostics in the neutral helium triplet at 10830 Å in principle allow full vector magnetometry of fine-scaled chromospheric fibrils. We present high-resolution spectropolarimetric observations of superpenumbral fibrils in the He I triplet with sufficient polarimetric sensitivity to infer their full magnetic field geometry. He I observations from the Facility Infrared Spectropolarimeter are paired with high-resolution observations of the Hα 6563 Å and Ca II 8542 Å spectral lines from the Interferometric Bidimensional Spectrometer from the Dunn Solar Telescope in New Mexico. Linear and circular polarization signatures in the He I triplet are measured and described, as well as analyzed with the advanced inversion capability of the "Hanle and Zeeman Light" modeling code. Our analysis provides direct evidence for the often assumed field alignment of fibril structures. The projected angle of the fibrils and the inferred magnetic field geometry align within an error of ±10°. We describe changes in the inclination angle of these features that reflect their connectivity with the photospheric magnetic field. Evidence for an accelerated flow (~40 m s-2) along an individual fibril anchored at its endpoints in the strong sunspot and weaker plage in part supports the magnetic siphon flow mechanism's role in the inverse Evershed effect. However, the connectivity of the outer endpoint of many of the fibrils cannot be established. Title: Solar Spectra Fe 1564.8 nm Line and a Least Squares Analysis Authors: Gottlieb, Amy; Penn, M. Bibcode: 2013AAS...22144501G Altcode: Observations from the NSO McMath-Pierce solar facility of sunspot spectra scans using the Fe I 1564.8 nm line have been re-examined. This data has shown a long-term trend with decreasing magnetic field strength and increasing temperature as discussed by Livingston, Penn and Svalgaard (2012). We recompute the Zeeman splitting, line depth, line width and Doppler shift in this line from about 200 spectra from the 1998-2002 data using a multi-Gaussian least-squares fitting technique. We find a direct correlation with the original values determined by Livingston but with an offset of about 50 Gauss, caused by a different spectral dispersion in the data than used in the original work. Title: He I Spectropolarimetry with FIRS: Towards Vector Magnetometry of Chromospheric Fibrils Plus New Diagnostics of Coronal Rain Authors: Schad, T. A.; Penn, M. J.; Lin, H.; Tritschler, A. Bibcode: 2012ASPC..463...25S Altcode: At the Dunn Solar Telescope, the Interferometric Bidimensional Spectrometer (IBIS) can measure the full Stokes vector of the Ca II 854.2 nm spectral line while the Facility Infrared Spectropolarimeter (FIRS) measures the Stokes vector of the He I triplet at 1083 nm. We analyze the He I triplet observed in two widely different features above NOAA AR 11295 on 19 September 2011 - thin (< 1″) chromospheric fibrils and a large-scale loop hosting a high-velocity coronal rain event. These two features are shown to first demonstrate the diagnostic potential of the He I triplet for magnetic fields in the chromosphere/transition region and second to stress the need to pair large-aperture facilities with flexible instrumentation. Inversions of the He I triplet near the penumbral boundary return azimuthal directions of the magnetic field aligned with fine-scale fibrils observed in the line core of Ca II. The coronal rain event shows Doppler velocities up to 195 km s-1, among the largest reported. We observe measurable polarization within the raining material, which may be a good magnetic diagnostic of chromospheric-like material higher in the corona within condensating loops. Title: Decreasing Sunspot Magnetic Fields Explain Unique 10.7 cm Radio Flux Authors: Livingston, W.; Penn, M. J.; Svalgaard, L. Bibcode: 2012ApJ...757L...8L Altcode: Infrared spectral observations of sunspots from 1998 to 2011 have shown that on average sunspots changed, the magnetic fields weakened, and the temperatures rose. The data also show that sunspots or dark pores can only form at the solar surface if the magnetic field strength exceeds about 1500 G. Sunspots appear at the solar surface with a variety of field strengths, and during the period from 1998 to 2002 a histogram of the sunspot magnetic fields shows a normal distribution with a mean of 2436 ± 26 G and a width of 323 ± 20 G. During this observing period the mean of the magnetic field distribution decreased by 46 ± 6 G per year, and we assume that as the 1500 G threshold was approached, magnetic fields appeared at the solar surface which could not form dark sunspots or pores. With this assumption we propose a quantity called the sunspot formation fraction and give an analytical form derived from the magnetic field distribution. We show that this fraction can quantitatively explain the changing relationship between sunspot number and solar radio flux measured at 10.7 cm wavelengths. Title: Multi-wavelength Spectropolarimetry Of A Sunspot Superpenumbra With Firs And Ibis Authors: Schad, Thomas A.; Tritschler, A.; Penn, M. J. Bibcode: 2012AAS...22020302S Altcode: Extending nearly radially from magnetic field concentrations like sunspot umbrae or pores, threadlike fibrils observed in the chromosphere and transition region host a variety of dynamic behavior and have long been considered local tracers for the magnetic field. Morphologically, fibrils are similar to spicules seen on the limb. The connectivity of fibrils outside of the magnetic field concentrations with the photosphere and/or corona is not well understood, and probing the magnetic field in these features remains challenging. In this contribution we describe multi-wavelength spectropolarimetric observations from the Dunn Solar Telescope in New Mexico using the Facility Infrared Spectropolarimeter (FIRS) and the Interferometric BiDimensional Spectropolarimeter (IBIS). FIRS performs high resolution slit spectropolarimetry in the He I triplet at 1083 nm, which is a promising diagnostic of chromospheric vector fields. Significant progress has been made to boost the accuracy and sensitivity of these measurements. Here we present measurements of an active region sunspot at a spatial resolution of 0.3 arcsec and an RMS noise in Stokes Q,U,V spectra down to 0.0003 in units of the local continuum (SNR > 3300). We perform full inversions of these spectra taking into account both Zeeman and Hanle effects. Initial results lend support for field-aligned fibrils near the penumbral boundary of a sunspot. Jointly with the FIRS observations, we use IBIS to observe the Stokes vectors of Ca II 854.2 nm and Fe I 617.3 nm and the intensity spectrum of H-alpha 656.3 nm. As a spectral imaging instrument, IBIS rapidly scans through the three spectral lines over a 45'' by 95'' FOV at an overall cadence of 50 seconds, allowing a much better description the dynamics of fibrils observed by both FIRS and IBIS. Title: Decreasing Sunspot Magnetic Fields Explain Unique 10.7cm Radio Flux Authors: Penn, Matthew J.; Livingston, W.; Svalgaard, L. Bibcode: 2012AAS...22011004P Altcode: Infrared spectral observations of sunspots from 1998-2011 have shown that on average sunspots changed; the magnetic fields weakened and the temperatures rose. The data also show that sunspots or dark pores can only form at the solar surface only if the magnetic field strength exceeds 1500 Gauss. Sunspots appear at the solar surface with a variety of field strengths, and during the period from 1998-2002 a histogram of the sunspot magnetic fields shows a normal distribution with a mean near 2400 Gauss and a width of about 340 Gauss. During this observing period the mean of the magnetic field distribution decreased by about 64 Gauss per year, and we assume that as the 1500 Gauss threshold was approached, magnetic fields appeared at the solar surface which could not form dark sunspots or pores With this assumption we propose a quantity called the sunspot formation fraction and give an analytical form derived from the magnetic field distribution. We show this fraction can quantitatively explain the changing elationship between sunspot number and solar radio flux measured at 10.7cm wavelengths. Title: Coronal Rain Observed On-disk with He I Spectropolarimetry from DST/FIRS Authors: Schad, Thomas A.; Penn, M. J.; Pietarila, A. Bibcode: 2012AAS...22031005S Altcode: Coronal rain refers to cool, dense blobs of plasma that presumably condense near the apex of hot coronal loops and then "rain" down upon the chromosphere traveling along curved loop-like paths. Considered to be the result of a thermal instability known as "catastrophic cooling", coronal rain places constraints on heating mechanisms for coronal loops. Nearly all observational studies of coronal rain, however, have been limited to the solar limb where cooler material within hot coronal loops is more readily identified. Here, we report observations of what we interpret to be the on-disk counterpart of coronal rain. Scanned spectropolarimetric observations in the He I triplet (1083 nm) from the Facility Infrared Spectropolarimeter (FIRS) reveal highly-redshifted material displaying an acceleration along curved trajectories terminating within a large sunspot (located at N17W21). Line-of-sight velocities in the He I triplet peak near 190 km/s, which can be consider high in relation to most coronal rain observations. This is also the largest redshift ever reported in the He I triplet. These curved loops correspond to an overarching loop structure seen in SDO/AIA anchored at its ends by a large sunspot and a group of pores. The loops observed with SDO/AIA display significant cooling as dark (EUV absorptive) blobs begin to form near the loop apex and then traverse along the same trajectories observed in the He I FIRS observations. Although the EUVI instrument of STEREO-A/SECCHI has a reduced temporal resolution compared to SDO/AIA, we are able to confidently match rain features in both spacecraft and thus stereoscopically reconstruct the three-dimensional trajectory to confirm the material is raining upon the solar surface. Title: Sunspot Dynamics as seen with CO 4666nm Spectroscopy Authors: Penn, Matthew J.; Schad, T. Bibcode: 2012AAS...22020610P Altcode: High resolution adaptive-optics corrected spectroscopy of sunspots using strong CO absorption lines at 4666nm was performed at the McMath-Pierce Solar Telescope using the NSO Array Camera. Active region NOAA 11158 was observed after the X-class flare on 17 Feb 2011. Several hours of rapid cadence scans reveal changes in umbral bright points, Evershed flows, flows along a sheer zone and penumbral fibrils as seen with the cool CO lines. Solar oscillations are studied, and the chromospheric structure associated with the regions of CO absorption are examined using 854.2nm Ca spectroscopy. Title: Long-term evolution of sunspot magnetic fields Authors: Penn, Matthew J.; Livingston, William Bibcode: 2011IAUS..273..126P Altcode: 2010arXiv1009.0784P Independent of the normal solar cycle, a decrease in the sunspot magnetic field strength has been observed using the Zeeman-split 1564.8nm Fe I spectral line at the NSO Kitt Peak McMath-Pierce telescope. Corresponding changes in sunspot brightness and the strength of molecular absorption lines were also seen. This trend was seen to continue in observations of the first sunspots of the new solar Cycle 24, and extrapolating a linear fit to this trend would lead to only half the number of spots in Cycle 24 compared to Cycle 23, and imply virtually no sunspots in Cycle 25.

We examined synoptic observations from the NSO Kitt Peak Vacuum Telescope and initially (with 4000 spots) found a change in sunspot brightness which roughly agreed with the infrared observations. A more detailed examination (with 13,000 spots) of both spot brightness and line-of-sight magnetic flux reveals that the relationship of the sunspot magnetic fields with spot brightness and size remain constant during the solar cycle. There are only small temporal variations in the spot brightness, size, and line-of-sight flux seen in this larger sample. Because of the apparent disagreement between the two data sets, we discuss how the infrared spectral line provides a uniquely direct measurement of the magnetic fields in sunspots. Title: Probing the Solar Atmosphere Using Oscillations of Infrared CO Spectral Lines Authors: Penn, M. J.; Schad, T.; Cox, E. Bibcode: 2011ApJ...734...47P Altcode: 2010arXiv1012.2371P Oscillations were observed across the whole solar disk using the Doppler shift and line center intensity of spectral lines from the CO molecule near 4666 nm with the National Solar Observatory's McMath/Pierce solar telescope. Power, coherence, and phase spectra were examined, and diagnostic diagrams reveal power ridges at the solar global mode frequencies to show that these oscillations are solar p-modes. The phase was used to determine the height of formation of the CO lines by comparison with the IR continuum intensity phase shifts as measured in Kopp et al. we find that the CO line formation height varies from 425 km < z < 560 km as we move from disk center toward the solar limb 1.0 > μ > 0.5. The velocity power spectra show that while the sum of the background and p-mode power increases with height in the solar atmosphere as seen in previous work, the power in the p-modes only (background subtracted) decreases with height. The CO line center intensity weakens in regions of stronger magnetic fields, as does the p-mode oscillation power. Across most of the solar surface the phase shift is larger than the expected value of 90° for an adiabatic atmosphere. We fit the phase spectra at different disk positions with a simple atmospheric model to determine that the acoustic cutoff frequency is about 4.5 mHz with only small variations, but that the thermal relaxation frequency drops significantly from 2.7 to 0 mHz at these heights in the solar atmosphere. Title: A Decade of Diminishing Sunspot Vigor Authors: Livingston, W. C.; Penn, M.; Svalgard, L. Bibcode: 2011SPD....42.1721L Altcode: 2011BAAS..43S.1721L 1A Decade of Diminishing Sunspot Vigor

William Livingston1

Matt Penn1

Leif Svalgard2

Sunspots are small dark areas on the solar disk where internal magnetism, 1500 to 3500 Gauss, has been buoyed to the surface. (Spot life times are the order of one day to a couple of weeks or more. They are thought to be dark because convection inhibits the outward transport of energy there). Their "vigor” can be described by spot area, spot brightness intensity, and magnetic field. From 2001 to 2011 we have measured field strength and brightness at the darkest position in umbrae of 1750 spots using the Zeeman splitting of the Fe 1564.8 nm line. Only one observation per spot per day is carried out during our monthly telescope time of 3-4 days average. Over this interval the temporal mean magnetic field has declined about 500 Gauss and mean spot intensity has risen about 20%. We do not understand the physical mechanism behind these changes or the effect, if any, it will have on the Earth environment.

1.

wcl@noao.edu</u> mpenn@noao.edu

2.

leif@leif.org Title: High-Resolution He I Spectropolarimetry of Chromospheric Fibrils Authors: Schad, Thomas A.; Penn, M. J. Bibcode: 2011SPD....42.0305S Altcode: 2011BAAS..43S.0305S Of spectral diagnostics for the magnetic field in the solar chromosphere, the He I triplet at 1083 nm offers a comparatively simple means to determine both the magnitude and direction of the field vector. The triplet forms over a narrow range of heights when compared to strong optical lines, and recently the mechanisms that influence its polarization have been well characterized, thus allowing inversions of the magnetic field from observed Stokes profiles. We discuss recent work with the Facility Infrared Spectropolarimeter (FIRS) at the Dunn Solar Telescope (DST), New Mexico, USA to measure and infer the magnetic field vector of chromospheric fibrils. FIRS is designed to perform fast diffraction-limited dual-beam spectropolarimetry simultaneously at visible and infrared wavelengths through the use of multiple slits and narrowband filters. It can be operated in congress with the High Order Adaptive Optics (HOAO) system of the DST as well as with the Interferometric BiDimensional Spectropolarimeter (IBIS). Here we present high-resolution FIRS observations of chromospheric fibrils which employ the HOAO system under great seeing. We calibrate these observations for the full effect of the FIRS-DST combined analysis system on the Stokes vector which allow us to define the observed Stokes geometry with respect to solar coordinates. Full inversions of our measurements incorporating the effects of atomic polarization, the Hanle effect, and the Zeeman effect will be presented showing support for chromospheric fibrils that are aligned with the magnetic field direction. Title: Probing the Solar Atmosphere Using Oscillations of Infrared CO Spectral Lines Authors: Penn, Matthew J.; Schad, T.; Cox, E. Bibcode: 2011SPD....42.1702P Altcode: 2011BAAS..43S.1702P Oscillations were observed across the whole solar disk using the Doppler shift and line center intensity of spectral lines from the CO molecule near 4666 nm with the National Solar Observatory's McMath/Pierce solar telescope. Power, coherence, and phase spectra were examined, and diagnostic diagrams reveal power ridges at the solar global mode frequencies to show that these oscillations are solar p-modes. The phase was used to determine the height of formation of the CO lines by comparison with the IR continuum intensity phase shifts as measured in Kopp et al., 1992; we find the CO line formation height varies from 425 < z < 560 km as we move from disk center towards the solar limb 1.0 > mu > 0.5. The velocity power spectra show that while the sum of the background and p-mode power increases with height in the solar atmosphere as seen in previous work, the power in the p-modes only (background subtracted) decreases with height. The CO line depth weakens in regions of stronger magnetic fields, as does the p-mode oscillation power. Across most of the solar surface the phase shift is larger than the expected value of 90 degrees for an adiabatic atmosphere. We fit the phase spectra at different disk positions with a simple atmospheric model to determine that the acoustic cutoff frequency is about 4.5 mHz with only small variations, but that the thermal relaxation frequency drops significantly from 2.7 to 0 mHz at these heights in the solar atmosphere. Title: Spectropolarimetry of Chromospheric Magnetic and Velocity Structure Above Active Regions Authors: Schad, T. A.; Jaeggli, S. A.; Lin, H.; Penn, M. J. Bibcode: 2011ASPC..437..483S Altcode: 2011arXiv1101.0631S Active regions often host large-scale gas flows in the chromosphere presumably directed along curved magnetic field lines. Spectropolarimetric observations of these flows are critical to understanding the nature and evolution of their anchoring magnetic structure. We discuss recent work with the Facility Infrared Spectropolarimeter (FIRS) located at the Dunn Solar Telescope in New Mexico to achieve high-resolution imaging-spectropolarimetry of the Fe I lines at 630 nm, the Si I line at 1082.7 nm, and the He I triplet at 1083 nm. We present maps of the photospheric and chromospheric magnetic field vector above a sunspot as well as discuss characteristics of surrounding chromospheric flow structures. Title: IR spectroscopy of COmosphere dynamics with the CO first overtone band Authors: Schad, T. A.; Penn, M. J. Bibcode: 2010AN....331..589S Altcode: 2010arXiv1008.5375S We discuss observations of the weak first overtone (\Delta\nu=2) CO absorption band near 2300 nm with the U.S. National Solar Observatory Array Camera (NAC), a modern mid-infrared detector. This molecular band provides a thermal diagnostic that forms lower in the atmosphere than the stronger fundamental band near 4600 nm. The observed center-to-limb increase in CO line width qualitatively agrees with the proposed higher temperature shocks or faster plasma motions higher in the COmosphere. The spatial extent of chromospheric shock waves is currently at or below the diffraction limit of the available CO lines at existing telescopes. Five minute period oscillations in line strength and measured Doppler shifts are consistent with the p-mode excitation of the photospheric gas. We also show recent efforts at direct imaging at 4600 nm. We stress that future large-aperture solar telescopes must be teamed with improved, dynamic mid-infrared instruments, like the NAC, to capitalize on the features that motivate such facilities. Title: Structural Invariance of Sunspot Umbrae over the Solar Cycle: 1993 - 2004 Authors: Schad, T. A.; Penn, M. J. Bibcode: 2010SoPh..262...19S Altcode: 2010SoPh..tmp...22S; 2009arXiv0912.2370S Measurements of maximum magnetic flux, minimum intensity, and size are presented for 12 967 sunspot umbrae detected on the National Aeronautics and Space Administration/National Solar Observatory (NASA/NSO) spectromagnetograms between 1993 and 2004 to study umbral structure and strength during the solar cycle. The umbrae are selected using an automated thresholding technique. Measured umbral intensities are first corrected for center-to-limb intensity dependence. Log-normal fits to the observed size distribution confirm that the size-spectrum shape does not vary with time. The intensity - magnetic-flux relationship is found to be steady over the solar cycle. The dependence of umbral size on the magnetic flux and minimum intensity are also independent of the cycle phase and give linear and quadratic relations, respectively. While the large sample size does show a low-amplitude oscillation in the mean minimum intensity and maximum magnetic flux correlated with the solar cycle, this can be explained in terms of variations in the mean umbral size. These size variations, however, are small and do not substantiate a meaningful change in the size spectrum of the umbrae generated by the Sun. Thus, in contrast to previous reports, the observations suggest the equilibrium structure, as manifested by the invariant size-magnetic field relationship, as well as the mean size (i.e., strength) of sunspot umbrae do not significantly depend on the solar-cycle phase. Title: FIRS: a new instrument for photospheric and chromospheric studies at the DST. Authors: Jaeggli, S. A.; Lin, H.; Mickey, D. L.; Kuhn, J. R.; Hegwer, S. L.; Rimmele, T. R.; Penn, M. J. Bibcode: 2010MmSAI..81..763J Altcode: The simultaneous observation of select spectral lines at optical and infrared wavelengths allows for the determination of the magnetic field at several photospheric and chromospheric heights and thus the 3D magnetic field gradient in the solar atmosphere. The Facility Infrared Spectropolarimeter (FIRS) is a newly completed, multi-slit, dual-beam spectropolarimeter installed at the Dunn Solar Telescope (DST) at Sacramento Peak (NSO/SP). Separate optics and polarimeters simultaneously observe two band-passes at visible and infrared wavelengths with a choice of two modes: the Fe I 6302 Å and 15648 Å lines in the photosphere; or the Fe I 6302 Å and He I 10830 Å line in the photosphere and high chromosphere, respectively. FIRS can also operate simultaneously with a white light camera, G-band imager, and the Interferometric Bi-dimensional Spectrometer (IBIS) observing the mid-chromospheric Ca II 8542 Å line. The instrument uses four parallel slits to sample four slices of the solar surface simultaneously to achieve fast, diffraction-limited precision imaging spectropolarimetry, enabling the study of MHD phenomena with short dynamic time scales. Title: Are Sunspots Different During This Solar Minimum? Authors: Livingston, W.; Penn, M. Bibcode: 2009EOSTr..90..257L Altcode: For hundreds of years, humans have observed that the Sun has displayed activity where the number of sunspots increases and then decreases at approximately 11-year intervals. Sunspots are dark regions on the solar disk with magnetic field strengths greater than 1500 gauss (see Figure 1), and the 11-year sunspot cycle is actually a 22-year cycle in the solar magnetic field, with sunspots showing the same hemispheric magnetic polarity on alternate 11-year cycles. The last solar maximum occurred in 2001, and the magnetically active sunspots at that time produced powerful flares causing large geomagnetic disturbances and disrupting some space-based technology. But something is unusual about the current sunspot cycle. The current solar minimum has been unusually long, and with more than 670 days without sunspots through June 2009, the number of spotless days has not been equaled since 1933 (see http://users.telenet.be/j.janssens/Spotless//Spotless.html). The solar wind is reported to be in a uniquely low energy state since space measurements began nearly 40 years ago [Fisk and Zhao, 2009]. Title: Evershed Outflow During Solar Cycle 23 Authors: Penn, Matthew J.; Schad, T. Bibcode: 2009SPD....40.0907P Altcode: We analyze several thousand Doppler observations of Evershed outflow in sunspot penumbrae taken at the National Solar Observatory's Kitt Peak Vacuum Telescope from 1993 to 2003. We compare the mean penumbral flow vector components with properties of the sunspot, latitude of the sunspot, and search for evolution of the components as a function of time. We discuss how our findings relate to measurements of sunspot magnetic helicity. Title: Near IR observations of Quiet Chromosphere Authors: Prasad Choudhary, Debi; Deng, N.; Tejamoortula, U.; Penn, M. J. Bibcode: 2009SPD....40.1005P Altcode: We have carried out the observations of quiet solar limb during April 29 to May 1, 2008, March 9-13, 2009 using the vertical spectrograph at the focal plane of McMath-Pierce telescope at Kitt Peak National Observatory. The solar limb was mostly featureless during the observations. The New Infrared Array (NAC) at the exit port of the spectrograph has been used to record the limb spectrum at HeI 1083.0 nm, Hydrogen Paschen beta at 1281.8 nm and Brackett gamma 2165.5 nm wavelength regions. The NAC is a 1024 x 1024 InSb Alladin III Detector operating over 1-5 micron range with high density sampling at 0.018 arc second/pixel. The all-reflective optical train minimizes number of surfaces and eliminates ghosts leading to low scatter, ghost-free optics. The close-cycle cryogenic provides a stable cooling environment over six hour period with an accuracy of about 0.01K leading to low dark current. The low read out noise combined with low scattered light and dark current makes NAC an ideal detector for making high quality infrared spectral observations of solar limb. In this presentation, we shall compare the line parameters of these lines around the solar disk.

Acknowledgements:

This work is supported by NSF under grant ATM 05-48952 and by NASA under grant NNX08AQ32G. Title: Dynamics of Quiet Solar Chromosphere at the Limb Authors: Choudhary, D.; Tejomoortula, U.; Penn, M. J. Bibcode: 2008AGUFMSH23A1622C Altcode: We have observed the solar limb using 1024 × 1024 InSb Near Infrared Camera and Spectroheliograph at McMath-Pierce telescope during the solar minimum period of April 29 to May 1, 2008. A 120 micron slit, corresponding to 0.3 arc second was aligned perpendicular to the solar limb for the observations. The slit spectrum with a resolution of 0.036 Å corresponding to about 05 to 1.0 km/s were obtained in the wavelength regions of HeI 10830 Å, Hydogen Paschen α 12818 Å and Hydrogen Brackett γ 21661 Å. Excellent seeing conditions and the use of adaptive optics produced stable observing conditions during most of the observations. We present the results of line width variation as a function of chromospheric height around the solar limb. Title: A New Era in Solar Thermal-IR Astronomy: the NSO Array Camera (NAC) on the McMath-Pierce Telescope Authors: Ayres, T.; Penn, M.; Plymate, C.; Keller, C. Bibcode: 2008ESPM...12.2.74A Altcode: The U.S. National Solar Observatory Array Camera (NAC) is a cryogenically cooled 1Kx1K InSb ``Aladdin" array that recently became operational at the McMath-Pierce facility on Kitt Peak, a high dry site in the southwest U.S. (Arizona). The new camera is similar to those already incorporated into instruments on nighttime telescopes, and has unprecedented sensitivity, low noise, and excellent cosmetics compared with the Amber Engineering (AE) device it replaces. (The latter was scavenged from a commercial surveillance camera in the 1990's: only 256X256 format, high noise, and annoying flatfield structure). The NAC focal plane is maintained at 30 K by a mechanical closed-cycle helium cooler, dispensing with the cumbersome pumped--solid-N2 40 K system used previously with the AE camera. The NAC linearity has been verified for exposures as short as 1 ms, although latency in the data recording holds the maximum frame rate to about 8 Hz (in "streaming mode"). The camera is run in tandem with the Infrared Adaptive Optics (IRAO) system. Utilizing a 37-actuator deformable mirror, IRAO can--under moderate seeing conditions--correct the telescope image to the diffraction limit longward of 2.3 mu (if a suitable high contrast target is available: the IR granulation has proven too bland to reliably track). IRAO also provides fine control over the solar image for spatial scanning in long-slit mode with the 14 m vertical "Main" spectrograph (MS). A 1'X1' area scan, with 0.5" steps orthogonal to the slit direction, requires less than half a minute, much shorter than p-mode and granulation evolution time scales. A recent engineering test run, in April 2008, utilized NAC/IRAO/MS to capture the fundamental (4.6 mu) and first-overtone (2.3 mu) rovibrational bands of CO, including maps of quiet regions, drift scans along the equatorial limbs (to measure the off-limb molecular emissions), and imaging of a fortuitous small sunspot pair, a final gasp, perhaps, of Cycle 23. Future work with the NAC will emphasize pathfinding toward the next generation of IR imaging spectrometers for the Advanced Technology Solar Telescope, whose 4 m aperture finally will bring sorely needed high spatial resolution to daytime infrared astronomy. In the meantime, the NAC is available to qualified solar physicists from around the world to conduct forefront research in the 1-5 mu region, on the venerable--but infrared friendly--McMath-Pierce telescope. Title: The Facility IR Spectropolarimeter for the Dunn Solar Telescope Authors: Jaeggli, S. A.; Lin, H.; Mickey, D. L.; Kuhn, J. R.; Hegwer, S. L.; Rimmele, T. R.; Penn, M. J. Bibcode: 2008AGUSMSH31A..11J Altcode: The Facility IR Spectropolarimeter(FIRS) is a multi-slit spectropolarimeter designed for the Dunn Solar Telescope (DST) at the National Solar Observatory on Sacramento Peak (NSO/SP) in New Mexico to study magnetism on the solar surface. The instrument samples adjacent slices of the solar surface using four parallel slits to achieve high cadence, diffraction-limited, precision imaging-spectropolarimetry. Due to the versatile, multi-armed design of the spectrograph, up to four spectral lines at visible and infrared wavelengths, covering four different heights in the solar atmosphere, can be observed simultaneously. In this poster-paper we will describe the design, capabilities, and performance of the instrument. Title: Solar Cycle Dependence of Umbral Magneto-Induced Line Broadening Authors: Schad, T. A.; Penn, M. J. Bibcode: 2008AGUSMSP41B..06S Altcode: Studies of the solar cycle dependence of peak umbral magnetic field strength have focused upon measurements of continuum intensity and the Zeeman splitting of infrared spectral lines. Here we extend the discussion into a measurement of effective line width using eleven years of spectromagnetograms from the Kitt Peak Vacuum Telescope (KPVT). The KPVT observed the 868.8 nm Fe I absorption line in opposing states of circular polarization between 1992 and 2003, deriving full-disk images of line-of-sight (LOS) velocity, LOS magnetic flux, continuum intensity, equivalent line width, and central line depth. We determine an effective spectral line width through a relation of the measured equivalent line widths and central line depths. Developing a basic model of the Stokes line profiles using the Seares formalism, we illustrate that a change in the effective line width within the umbra as determined using the KPVT data is consistent with the change in the Zeeman splitting. We discuss the effect of observed distance from disk center, stray light, and the unknown inclination angle of the magnetic field. Within individual sunspots observed near disk center, the determined effective line width decreases with distance from the umbral core consistent with the studied magnetic field gradient. Measurements of different sunspots show a clear dependence on umbral size consistent with previous studies of the umbral magnetic field. Using this effective line width as a diagnostic for magnetic field, we examine the dependence of maximum magnetic field strength on the phase of the solar cycle. We present a comprehensive statistical analysis using a sample size of over 3500 umbral measurements. Title: Near Infrared Observations of Solar Granulation Authors: Penn, M. Bibcode: 2008AGUSMSP41B..01P Altcode: The near infrared continuum provides a unique window for the study of solar granulation. The opacity minimum at a wavelength of 1600nm allows granulation to be imaged at a depth of roughly 50km below the optical depth unity (500nm) level, and the continuum at 5000nm, formed by H- free-free opacity, arises from a layer roughly 70 km above the optical depth unity level. There are two challenges in observing granulation in the infrared; image motion and distortion from the Earth's atmosphere, and telescopic resolution at longer wavelengths. To meet these challenges we present data from the National Solar Observatory McMath-Pierce Main Telescope (currently the largest solar telescope with a 1.6m aperture) using adaptive optics and post-processing techniques to remove seeing effects. Title: Solar Cycle Changes in Sunspot Umbral Intensity Authors: Penn, M. J.; MacDonald, R. K. D. Bibcode: 2007ApJ...662L.123P Altcode: The minimum intensities of sunspot umbrae were measured from 1992 through 2003 using the National Solar Observatory Kitt Peak Vacuum Telescope spectromagnetograph data. The resulting 3931 umbral measurements reveal a solar cycle variation in the umbral intensity, with umbrae appearing brighter on average at cycle minimum and darker at cycle maximum. Recent studies of umbral intensity have been in direct conflict with each other, showing decreasing, increasing, or no umbral intensity trends. By providing a longer temporal baseline, our new measurements uncover a solar cycle oscillation in umbral intensity. From this new perspective we show how previous studies agree with our work and with each other when the same phase of the solar cycle is examined. Also in agreement with other investigators, the solar cycle variation in the daily average umbral area, the lognormal distribution of umbral area, and the near constancy of the mean umbral radius during the solar cycle are seen in this data. Title: Further Investigations of the Umbral Intensity of Sunspots Authors: MacDonald, Rachel; Penn, M. J. Bibcode: 2007AAS...210.9201M Altcode: 2007BAAS...39R.208M In the summer of 2006 the minimum umbral intensity of sunspots was studied for over 3000 sunspots observed by the Kitt Peak Vacuum Telescope from November, 1992, to September, 2003. A trend was found in the variation of the minimum intensity that was tied to the solar cycle--minimum umbral intensity increased from solar maximum to minimum, and decreased from solar minimum to maximum. These results agreed with several previous works on the subject. In the fall of 2006 the minimum umbral intensity was investigated once more using sunspots observed through the Michaelson Doppler Imager (MDI) instrument on the Solar and Heliospheric Observatory (SOHO) satellite. The same analysis software was used on the MDI data as on the KPVT data, studying over 4500 sunspots from June, 1996, to December, 2005. Results of this analysis will be compared with the KPVT results, and with those of previous works.

This work is carried out through the National Solar Observatory Research Experiences for Undergraduate (REU) site program, which is co-funded by the Department of Defense in partnership with the National Science Foundation REU Program. Title: Recent Results From The NSO Array Camera Authors: Plymate, Claude; Penn, M. J. Bibcode: 2007AAS...210.2409P Altcode: 2007BAAS...39..130P The McMath-Pierce Solar Telescope (McMP) utilizes an all-reflecting optical system of 1.6-meter aperture, still the largest among solar telescopes. This unique optical configuration allows for high spatial, spectral and temporal infrared mapping of the solar surface. The National Solar Observatory (NSO) has invested in a robust IR instrumentation development program at the McMP. Now available as a facility instrument is a 10242 InSb array camera for use in the 1 - 5 µm thermal infrared. Known as the NSO Array Camera (NAC), it was designed to couple to the telescope's very high dispersion spectrograph. The spectral imaging capability of the NAC is enhanced with a low-order IR adaptive optics (IRAO) system designed to correct seeing to the diffraction limit of the telescope under moderate seeing conditions redward of 2.3 µm. The IRAO can scan the corrected image across the spectrograph input slit allowing 2-D mapping of the solar surface. Liquid crystal retardation modulators and polarizing optics have been added to the spectrograph to enable the NAC to record IR Stokes polarimetry data. Presented here are movies of solar granulation at 2.2 µm obtained with the NAC/IRAO, Stokes polarimetric spectra of the 1.56 µm g=3 Fe I absorption line, and sample observations of the CO 4.6 µm absorption lines. Title: Observations of Solar Structures and Oscillations with Infrared CO Absorption Lines Authors: Penn, Matthew J. Bibcode: 2007AAS...21012003P Altcode: 2007BAAS...39..245P Observations of several infrared absorption lines from the CO molecule have been made with the NSO Array Camera at the McMath/Pierce Telescope at Kitt Peak. The NAC provides cleaner slit spectra than previously obtained with older camera systems, and we are able to fit the CO line profiles to measure line depth, position and width. Spectroheliograms are produced from these quantities,and the observations show the well-known CO limb darkening, emission just above the continuum limb, increasing line width at the limb, and decreased absorption line strength near a hot, presumably magnetic feature. Time sequence observations show solar oscillations in the line strength and central wavelength and continuum brightness, and for the first time oscillations are measured using the CO line width. Velocity maps in the CO lines near the limb show steady horizontal flows in supergranule-like features. Title: Penumbral Moving Magnetic Features Authors: Penn, M. J.; Jaeggli, S. A.; Henney, C. J.; Luszcz, S.; Walton, S. R. Bibcode: 2006ASPC..358...31P Altcode: Moving magnetic features are observed in the penumbrae of two sunspots with time sequences of vector magnetic field measurements taken in the infrared Fe I 1565 nm spectral line (g=3). These features move with similar radial velocities as previously observed continuum and G-band features, and confirm a short sequence of penumbral magnetic observations in the visible. These features move with similar speeds to the moving magnetic features seen outside sunspot penumbrae, and in some cases they are seen to cross the penumbral boundary and move across the sunspot moat. Magnetic and flow parameters are briefly compared with predictions from the moving flux tube model. Title: Temporal Changes in Sunspot Umbral Magnetic Fields and Temperatures Authors: Penn, M. J.; Livingston, W. Bibcode: 2006ApJ...649L..45P Altcode: We have observed high-resolution intensity spectra near the Fe I 1564.8 nm line at a single umbral point corresponding to the darkest position in over 900 sunspots from 1998 through 2005. From these data we determine that the maximum sunspot magnetic fields have been decreasing at about 52 G yr-1. The same data set shows a concurrent increase in the normalized umbral intensity from 0.60 to 0.75 (corresponding to a blackbody temperature rise from 5137 to 5719 K) and a decrease of more than 50% in the molecular OH line strength. The magnetic field and intensity changes observed over time in the sunspot umbrae from different spots behave in the same way as the magnetic field and intensity changes observed spatially across single sunspots. Title: NAC Observations of an X1.8 Flare Authors: Penn, Matthew J. Bibcode: 2006SPD....37.0811P Altcode: 2006BAAS...38..232P The NSO Array Camera (NAC) observed He 1083nm spectral line profiles in the active region NOAA 10808 before, during and after the X1.8 flare of 13 Sep 2005. The NAC observations were made at the McMath-Pierce main telescope using the spectrograph and the IR grating. The spatial field-of-view was limited to the umbra and immediately surrounding penumbra, but the spectral coverage ranged from 1080 to 1085nm. Before the flare regions of strong downflows (30 km/s) are seen; during the flare very bright emission (2.5 times the continuum intensity) are seen in line center in several kernels near the umbral/penumbral boundary; and after the flare, narrow spatial structures are seen with broad spectral absorption profiles showing downflows exceeding 100 km/s. Title: Site testing for the Advanced Technology Solar Telescope Authors: Hill, F.; Beckers, J.; Brandt, P.; Briggs, J.; Brown, T.; Brown, W.; Collados, M.; Denker, C.; Fletcher, S.; Hegwer, S.; Horst, T.; Komsa, M.; Kuhn, J.; Lecinski, A.; Lin, H.; Oncley, S.; Penn, M.; Radick, R.; Rimmele, T.; Socas-Navarro, H.; Streander, K. Bibcode: 2006SPIE.6267E..1TH Altcode: 2006SPIE.6267E..59H The Advanced Solar Technology Telescope (ATST) is a 4-m solar telescope being designed for high spatial, spectral and temporal resolution, as well as IR and low-scattered light observations. The overall limit of performance of the telescope is strongly influenced by the qualities of the site at which it is located. Six sites were tested with a seeing monitor and a sky brightness instrument for 1.5 to 2 years. The sites were Big Bear (California), Haleakala (Hawaii), La Palma (Canary Islands, Spain), Panguitch Lake (Utah), Sacramento Peak (New Mexico), and San Pedro Martir (Baja California, Mexico). In this paper we will describe the methods and results of the site survey, which chose Haleakala as the location of the ATST. Title: Large-scale Structures and their Role in Solar Activity Authors: Sankarasubramanian, K.; Penn, M.; Pevtsov, A. Bibcode: 2005ASPC..346.....S Altcode: No abstract at ADS Title: Polarization in Mercury's Exosphere Authors: Allen, J. E., Jr.; Penn, M. J. Bibcode: 2005ASPC..343..181A Altcode: The linear polarization states of the sodium D-lines in the exosphere of Mercury have been determined from high-resolution spectropolarimetric images acquired with a polarization analysis package coupled to a Fabry-Perot interferometer; the results were subsequently confirmed using an equivalent polarization package with a high-resolution spectrograph. Title: Solar Site Survey for the Advanced Technology Solar Telescope. I. Analysis of the Seeing Data Authors: Socas-Navarro, H.; Beckers, J.; Brandt, P.; Briggs, J.; Brown, T.; Brown, W.; Collados, M.; Denker, C.; Fletcher, S.; Hegwer, S.; Hill, F.; Horst, T.; Komsa, M.; Kuhn, J.; Lecinski, A.; Lin, H.; Oncley, S.; Penn, M.; Rimmele, T.; Streander, K. Bibcode: 2005PASP..117.1296S Altcode: 2005astro.ph..8690S The site survey for the Advanced Technology Solar Telescope concluded recently after more than 2 years of data gathering and analysis. Six locations, including lake, island, and continental sites, were thoroughly probed for image quality and sky brightness. The present paper describes the analysis methodology employed to determine the height stratification of the atmospheric turbulence. This information is crucial, because daytime seeing is often very different between the actual telescope aperture (~30 m) and the ground. Two independent inversion codes have been developed to simultaneously analyze data from a scintillometer array and a solar differential image monitor. We show here the results of applying them to a sample subset of data from 2003 May that was used for testing. Both codes retrieve a similar seeing stratification through the height range of interest. A quantitative comparison between our analysis procedure and actual in situ measurements confirms the validity of the inversions. The sample data presented in this paper reveal a qualitatively different behavior for the lake sites (dominated by high-altitude seeing) and the rest (dominated by near-ground turbulence). Title: The ATST Site Survey Authors: Hill, F.; Beckers, J.; Brandt, P.; Briggs, J. W.; Brown, T.; Brown, W.; Collados, M.; Denker, C.; Fletcher, S.; Hegwer, S.; Horst, T.; Komsa, M.; Kuhn, J.; Lecinski, A.; Lin, H.; Oncley, S.; Penn, M.; Radick, R.; Rimmele, T.; Socas-Navarro, H.; Soltau, D.; Streander, K. Bibcode: 2005AGUSMSP34A..04H Altcode: The Advanced Technology Solar Telescope (ATST) will be the world's largest aperture solar telescope, and is being designed for high resolution, IR, and coronal research. It must be located at a site that maximizes the scientific return of this substantial investment. We present the instrumentation, analysis and results of the ATST site survey. Two instrumentation sets were deployed at each of six sites to measure seeing as a function of height, and sky brightness as a function of wavelength and off-limb position. Analysis software was developed to estimate the structure function Cn2 as a function of height near the ground, and the results were verified by comparison with in-situ measurements. Additional software was developed to estimate the sky brightness. The statistics of the conditions at the sites were corrected for observing habits and the annualized hours of specific observing conditions were estimated. These results were used to identify three excellent sites suitable to host the ATST: Haleakala, Big Bear and La Palma. Among them, Haleakala is proposed as the optimal location of the ATST, La Palma and Big Bear being viable alternative sites. Title: Searching for Moving Magnetic Features at 1565 nm Authors: Jaeggli, S. A.; Penn, M. J.; Henney, C. J. Bibcode: 2005AGUSMSP41B..01J Altcode: Spectropolarimetric data of the active region 10663 was taken with the CSUN-NSO IR camera and the McMath-Pierce telescope on August 26, 2004 from 16:35 to 21:02 UT. Utilizing the Zeeman split Fe I line near 1565 nm, the data is processed to remove instrumental polarization and a Milne-Eddington inversion technique is applied. The results of the inversion are used to examine the physical properties and radial motions of moving magnetic features which appear to originate in the sunspot penumbra. Title: Moving Magnetic Features Inside the Penumbra of NOAO 10008 Authors: Luszcz, S. H.; Penn, M. J.; Jaeggli, S. A.; Henney, C. J. Bibcode: 2005AGUSMSP11A..05L Altcode: Over 30 years of observations and theories comprise the study of moving magnetic features (MMFs). MMFs, which often occur in opposite polarity pairs, migrate radially outward through the sunspot moat at speeds of about 1 km~s-1. A sequence of sixteen scans of the active region NOAO 10008 were taken using the NSO-CSUN IR camera at the NSO McMath-Pierce Solar Telescope on 24 June 2002 17:38-21:59. Using the Fe I absorption line at 1564.8nm, magnetogram images and maps of the magnetic field vector were produced, revealing magnetic features within the penumbra that appear to move radially outward at similar velocities and azimuth angles as those of MMFs in the moat. We use polar time slice images to measure the radial velocities of both types of features. This work is carried out through the National Solar Observatory Research Experiences for Undergraduate (REU) site program, which is co-funded by the Department of Defense in partnership with the National Science Foundation REU Program. Title: The 1564.6nm CN Line in Sunspots Authors: Penn, M. J.; Jaeggli, S. A. Bibcode: 2005AGUSMSP11A..02P Altcode: The line strength of CN absorption has been observed to vary with the continuum intensity within sunspots, and the Doppler shift of the CN line at 1564.6nm has been shown to reveal fast Evershed flows in the penumbra. We examine several sunspots observed from 2002-2005 using intensity spectroscopy and spectropolarimetry to determine the line strength, plasma flow velocity, and the local magnetic field configuration as functions of position in these sunspots. Title: Solar site testing for the Advanced Technology Solar Telescope Authors: Hill, Frank; Beckers, Jacques; Brandt, Peter; Briggs, John; Brown, Timothy; Brown, W.; Collados, Manuel; Denker, Carsten; Fletcher, Steven; Hegwer, Steven; Horst, T.; Komsa, Mark; Kuhn, Jeff; Lecinski, Alice; Lin, Haosheng; Oncley, Steve; Penn, Matthew; Rimmele, Thomas R.; Socas-Navarro, Hector; Streander, Kim Bibcode: 2004SPIE.5489..122H Altcode: The location of the Advanced Technology Solar Telescope (ATST) is a critical factor in the overall performance of the telescope. We have developed a set of instrumentation to measure daytime seeing, sky brightness, cloud cover, water vapor, dust levels, and weather. The instruments have been located at six sites for periods of one to two years. Here we describe the sites and instrumentation, discuss the data reduction, and present some preliminary results. We demonstrate that it is possible to estimate seeing as a function of height near the ground with an array of scintillometers, and that there is a distinct qualitative difference in daytime seeing between sites with or without a nearby lake. Title: The Advanced Technology Solar Telescope Site Survey Sky Brightness Monitor Authors: Lin, Haosheng; Penn, Matthew J. Bibcode: 2004PASP..116..652L Altcode: The Advanced Technology Solar Telescope (ATST) will be a 4 m aperture off-axis telescope with advanced high-resolution and low scattered light capabilities for the observation of the solar photosphere and corona. The site characteristics that are critical to the success of the ATST coronal observations are the sky brightness, the precipitable water vapor content, and the number and size distributions of the dust particles. Therefore, part of the ATST site survey effort is to obtain measurements of these atmospheric properties at all the potential ATST sites. The ATST site survey Sky Brightness Monitor (SBM) is a new instrument specifically developed for this task. The SBM is a modified externally occulted coronagraph capable of imaging the solar disk and sky simultaneously. The ability to image the Sun and the sky simultaneously greatly simplifies the calibration of the sky-brightness measurements. The SBM has a very simple optical configuration that makes it a compact and low-maintenance instrument. The SBM is sensitive to sky brightness below 1×10-6 disk center intensity, with a field of view extending from 4 to 8 Rsolar. It measures the solar disk and sky brightness at three continuum bandpasses located at 450, 530, and 890 nm. A fourth bandpass is centered at the 940 nm water vapor absorption band. With measurements of disk and sky brightness at these four wavelengths, site characteristics such as extinctions, aerosol content, and precipitable water vapor content can be derived. This paper documents the design, specifications, calibration procedures, and performance of the SBM. Title: Background-Induced Measurement Errors of the Coronal Intensity, Density, Velocity, and Magnetic Field Authors: Penn, M. J.; Lin, H.; Tomczyk, S.; Elmore, D.; Judge, P. Bibcode: 2004SoPh..222...61P Altcode: The effect of a background signal on the signal-to-noise ratio is discussed, with particular application to ground-based observations of emission lines in the solar corona with the proposed Advanced Technology Solar Telescope. The concepts of effective coronal aperture and effective coronal integration time are introduced. Specific expressions are developed for the 1σ measurement errors for coronal intensity, coronal electron density, coronal velocity, and coronal magnetic field measurements using emission lines and including a background. Title: Latest Results from the ATST Site Survey Authors: Hill, F.; Collados, M.; Navarro, H.; Beckers, J.; Brandt, P.; Briggs, J.; Brown, T.; Denker, C.; Hegwer, S.; Horst, T.; Komsa, M.; Kuhn, J.; Lin, H.; Oncley, S.; Penn, M.; Rimmele, T.; Soltau, D.; Streander, K. Bibcode: 2004AAS...204.6909H Altcode: 2004BAAS...36..795H We present the latest results and current status of the site survey portion of the Advanced Technology Solar Telescope (ATST) project. The ATST will provide high resolution solar data in the visible and IR. The site is a major factor determining the performance of the telescope. The most critical site characteristics are the statistics of daytime seeing quality and sky clarity. These conditions are being measured by a suite of instruments at three sites (Big Bear, Haleakala, La Palma). These sites were chosen from a set of six that have been tested starting in November 2001. The instrumentation includes a solar differential image motion monitor, an array of scintillometers, a miniature coronagraph, a dust monitor, and a weather station. The analysis of the data provides an estimate of the seeing as a function of height near the ground. We will present the latest results of the analysis of the survey data set. Title: IR Vector Magnetic Fields I: Instrumental Polarization Correction Authors: Jaeggli, S. A.; Penn, M. J. Bibcode: 2004AAS...204.3706J Altcode: 2004BAAS...36R.709J Instrumental polarization is evident in the spectra of active region 10008 taken with the CSUN-NSO IR camera at the McMath-Pierce telescope on June 24, 2002. Several iron lines near 15650 Å in the spectra exhibit Zeeman splitting. Using a technique described by Kuhn et. al. (1994) the original polarization is restored. For all Zeeman split lines in the spectra the corrected Stokes profiles for the Q and U components show symmetry, while Stokes V is made antisymmetric with no central component.

The observed Stokes vector is related to the true Stokes vector through the formula Strue = M-1 Sobs where M-1 is the inverse Mueller matrix. The correction coefficients from the Kuhn method are used to compute the inverse Mueller matrix for light path of the entire system. The expected inverse Mueller matrix is computed for the telescope at each scan time using a simple model described by Bernasconi (1997) but assuming the n and k values of the index of refraction are the same for each mirror surface. A least squares technique is used to fit this telescope model to the measured inverse Mueller matrix for the system. The telescope model can account for most of the measured cross-talk except for the observed Stokes Q to Stokes V cross-talk which is thought to occur in the polarimeter. Title: IR Vector Magnetic Fields II: Atomic and Molecular Line Polarization in a Sunspot Authors: Penn, M. J.; Jaeggli, S. A.; Henney, C. J.; Walton, S. R.; Ceja, J. A. Bibcode: 2004AAS...204.3705P Altcode: 2004BAAS...36..709P Full Stokes I,Q,U and V measurements of the active region NOAA 10008 were taken from 21-27 June 2002 at the NSO Kitt Peak McMath/Pierce solar telescope using the CSUN/NSO HgCdTe IR camera and polarimeter at 1565nm. The data is corrected for instrumental polarization as discussed in Paper I. Here the initial analysis of the atomic and molecular line polarization data is presented.

Inversion of the Fe I g=3 1564.8nm line data with a modified Skumanich and Lites Milne-Eddington technique is used to measure photospheric magnetic field parameters. A sequence of scans covering several hours of time shows evolution of the magnetic field. Examination of the linear polarization of the OH 1565.2nm shows curious temporal variation which results in a magnetic azimuth radically different from that measured using the photospheric lines. (Similar OH polarization behavior is seen in data from the CSUN San Fernando Observatory vacuum telescope taken with the CSUN/NSO camera in active region NOAA 10069 on 12 Aug 2002.) Finally, maps of the CN 1564.6nm Stokes I line shift show rapid penumbral Evershed flows and a curious signal in the sunspot umbra.

Some of this work is carried out through the National Solar Observatory Research Experiences for Undergraduate (REU) site program, which is co-funded by the Department of Defense in partnership with the National Science Foundation REU Program. Title: Magnetic Source of 16 Mar 2009 Filament Eruption: An Imagined VSO Study Authors: Penn, M. J. Bibcode: 2004AAS...204.5202P Altcode: 2004BAAS...36..754P There have been many studies of the famously geo-effective CME of 16 Mar 2009 and the associated filament eruption. The general features of the current model, where global sub-surface flows transport magnetic fields which weaken the overlying magnetic arcade and allow a tiny intra-network dipole to trigger the eruption, are mentioned. Particular emphasis is placed on the performance of the Virtual Solar Observatory with respect to this event. The multi-wavelength and multiple spatial scale nature of the VSO-retrieved data is shown to be essential to several studies of the filament, flare and CME. A movie-based VSO user interface facilitated data retrieval. Raw data access was critical in several cases, and pointers to the relevant calibration data were very helpful. The ability to retrieve magnetic extrapolation models from the VSO system aided in several studies of the filament eruption trajectory, as did the available in-situ data. Finally, the meshing of the public data with the open-PI data from several observatories was helpful, though improvements are suggested. Title: Extinction and Sky Brightness at Two Solar Observatories Authors: Penn, M. J.; Lin, H.; Schmidt, A. M.; Gerke, J.; Hill, F. Bibcode: 2004SoPh..220..107P Altcode: The Advanced Technology Solar Telescope site survey Sky Brightness Monitor simultaneously images the solar disk and the sky to about 8 solar radii in four wavelengths at 450, 530, 890 and 940 nm. One day of data from Mees Solar Observatory on Haleakala and from the National Solar Observatory at Sacramento Peak (Sunspot, New Mexico) are analyzed. Both sites show strong Rayleigh extinction, but while Haleakala shows a larger aerosol component, Sunspot shows a large variation in the aerosol component. Overall the Haleakala extinction varies as λ−2 whereas the Sunspot extinction changes from about λ−3.5 to about λ−2, suggesting an increasing aerosol component during the day. Water vapor absorption measurements from both sites are similar, though Sunspot shows larger time variations than Haleakala. The instrument-corrected sky brightness from both sites show comparable values, and again the Sunspot data show more variations. The sky brightness values show a radial dependence of sky brightness of r−0.1 at Haleakala, but a dependence of r−1.0 at Sunspot. The wavelength variation of the sky brightness at Haleakala is relatively constant at λ−1.5 but varies at Sunspot from λ−1.5 to λ−0.1 again suggesting an increasing aerosol contribution during the day at Sunspot. Finally, dust measurements near the ground are compared with the extinction wavelength exponent for data taken at Haleakala on 24 Feb. 2003. The measurements suggest more large dust particles are present near the ground than averaged over the whole air column. Title: Synergy of Research and EPO Programs at NSO Authors: Balasubramaniam, K. S.; Keil, S. L.; Penn, M. J.; Dooling, D.; Piano, P.; Diehl, J.; Hunter, R. Bibcode: 2003AGUFMED51C1215B Altcode: The National Solar Observatory with its facilities at Sunspot, NM and Tucson, AZ runs an extensive education and public outreach effort. Much of these efforts are coupled research and education efforts aimed across a spectrum that spans through school teachers, school students, undergraduate and graduate researchers, and the public. In this paper, we will describe the benefits and challenges the NSO program faces, and future prospects of these programs. Title: Imaging Spectropolarimetry of Ti I 2231 nm in a Sunspot Authors: Penn, M. J.; Cao, W. D.; Walton, S. R.; Chapman, G. A.; Livingston, W. Bibcode: 2003SoPh..215...87P Altcode: Spectro-polarimetric observations at 2231 nm were made of NOAA 10008 near the west solar limb on 29 June 2002 using the National Solar Observatory McMath-Pierce Telescope at Kitt Peak and the California State University Northridge - National Solar Observatory infrared camera. Scans of spectra in both Stokes I and Stokes V were collected; the intensity spectra were processed to remove strong telluric absorption lines, and the Stokes V umbral spectra were corrected for instrumental polarization. The sunspot temperature is computed using the continuum contrast and umbral temperatures down to about 3700 K are observed. A strong Ti i line at 2231.0 nm is used to probe the magnetic and velocity fields in the spot umbra and penumbra. Measurements of the Ti i equivalent width versus plasma temperature in the sunspot agree with model predictions. Zeeman splitting measurements of the Stokes I and Stokes V profiles show magnetic fields up to 3300 G in the umbra, and a dependence of the magnetic field on the plasma temperature similar to that which was seen using Fe i 1565 nm observations of the same spot two days earlier. The umbral Doppler velocity measurements are averaged in 16 azimuthal bins, and no radial flows are revealed to a limit of ± 200 m s−1. A Stokes V magnetogram shows a reversal of the line-of-sight magnetic component between the limb and disk center sides of the penumbra. Because the Ti i line is weak in the penumbra, individual spectra are averaged in azimuthal bins over the entire penumbral radial extent. The averaged Stokes V spectra show a magnetic reversal as a function of sunspot azimuthal angle. The mean penumbral magnetic field as measured with the Stokes V Zeeman component splitting is 1400 G. Several weak spectral lines are observed in the sunspot and the variation of the equivalent width versus temperature for four lines is examined. If these lines are from molecules, it is possible that lines at 2230.67, 2230.77, and 2231.70 nm originate from OH, while the line at 2232.21 nm may originate from CN. Title: Weak Infrared Molecular Lines Reveal Rapid Outflow in Cool Magnetic Sunspot Penumbral Fibrils Authors: Penn, M. J.; Cao, W. D.; Walton, S. R.; Chapman, G. A.; Livingston, W. Bibcode: 2003ApJ...590L.119P Altcode: New imaging spectropolarimetric observations of the Evershed flow in sunspot penumbrae using weak infrared molecular absorption lines are presented. A plane-polar coordinate system in the sunspot frame is defined, allowing averaging of many raw spectra. Molecular lines show Doppler shifts implying typical horizontal outflow speeds of 6 and up to 9 km s-1. The Ti I polarimetric spectra show the same rapid outflow and suggest an average penumbral magnetic field strength of 1400 G. While these observations show Doppler shifts of the entire line profile, the velocities are in better agreement with previous measurements from spectral line asymmetries. Title: Weak IR Lines Reveal Rapid Outflow in Cool Magnetic Penumbra Authors: Penn, M. J.; Cao, W. D.; Walton, S. R.; Chapman, G. A.; Livingston, W. Bibcode: 2003SPD....34.1106P Altcode: 2003BAAS...35..827P New imaging spectropolarimetric observations of the Evershed flow in sunspot penumbrae using weak infrared molecular absorption lines are presented. A plane-polar coordinate system in the sunspot frame is defined, allowing averaging of many raw spectra. Molecular lines show Doppler shifts implying typical horizontal outflow speeds of 6 to 9 km/sec. The Ti I polarimetric spectra show the same rapid outflow and suggest an average penumbral magnetic field strength of 1400 Gauss. While these observations show Doppler shifts of the entire line profile the velocities are in better agreement with previous measurements from spectral line asymmetries. Title: Temperature Dependence of Molecular Line Strengths and Fe i 1565 nm Zeeman Splitting in a Sunspot Authors: Penn, M. J.; Walton, S.; Chapman, G.; Ceja, J.; Plick, W. Bibcode: 2003SoPh..213...55P Altcode: Spectroscopic observations at 1565 nm were made in the eastern half of the main umbra of NOAA 9885 on 1 April 2002 using the National Solar Observatory McMath-Pierce Telescope at Kitt Peak with a tip-tilt image stabilization system and the California State University Northridge-National Solar Observatory infrared camera. The line depth of the OH blend at 1565.1 nm varies with the observed continuum temperature; the variation fits previous observations except that the continuum temperature is lower by 600 K. The equivalent width of the OH absorption line at 1565.2 nm shows a temperature dependence similar to previously published umbral molecular observations at 640 nm. A simple model of expected OH abundance based upon an ionization analogy to molecular dissociation is produced and agrees well with the temperature variation of the line equivalent width. A CN absorption line at 1564.6 nm shows a very different temperature dependence, likely due to complicated formation and destruction processes. Nonetheless a numerical fit of the temperature variation of the CN equivalent width is presented. Finally a comparison of the Zeeman splitting of the Fe i 1564.8 nm line with the sunspot temperature derived from the continuum intensity shows an umbra somewhat cooler for a given magnetic field strength than previous comparisons using this infrared 1564.8 nm line, but consistent with these previous infrared measurements the umbra is hotter for a given magnetic field strength than magnetic and temperature measurements at 630.2 nm would suggest. Differences between the 630.2 nm and 1564.8 nm umbral temperature and magnetic field relations are explained with the different heights of formation of the lines and continua at these wavelengths. Title: Science Objectives and Technical Challenges of the Advanced Technology Solar Telescope (Invited review) Authors: Rimmele, T.; Keil, S. L.; Keller, C.; Hill, F.; Penn, M.; Goodrich, B.; Hegwer, S.; Hubbard, R.; Oschmann, J.; Warner, M.; Dalrymple, N.; Radick, R.; Atst Team Bibcode: 2003ASPC..286....3R Altcode: 2003ctmf.conf....3R No abstract at ADS Title: Stokes V Profiles in a Post-flare Ca II 854.2nm Downflow Authors: Penn, M. J.; Jones, H. P. Bibcode: 2003ASPC..286..355P Altcode: 2003ctmf.conf..355P No abstract at ADS Title: Spectroscopic Detection of the 3.934 Micron Line of Si IX in the Solar Corona Authors: Judge, P. G.; Tomczyk, S.; Livingston, W. C.; Keller, C. U.; Penn, M. J. Bibcode: 2002ApJ...576L.157J Altcode: We report the detection of the 2s22p23P1-->0 line of Si IX using the McMath-Pierce telescope on Kitt Peak. Observations were made of the solar disk and at various heights above the limb between 2002 May 13 and 17, under nonideal sky conditions, using the 13.5 m vertical spectrograph and an InSb single-diode detector. We report a new rest wavelength for the line and discuss its potential use as a diagnostic of coronal magnetic fields using ground-based telescopes. Our observations give λrest=3.93434+/-0.00007 μm, consistent with earlier less accurate values, but it places the blue wing of the line under a strong telluric N2O line. In the active regions observed, the line's intensity is comparable to or larger than predicted in earlier work for the quiet Sun. Title: Polarization of the Sodium D-Lines in Mercury's Atmosphere Authors: Allen, J. E., Jr.; Penn, M. J.; Michael, B. P.; Branston, D.; Ceja, J. Bibcode: 2002DPS....34.0803A Altcode: 2002BAAS...34..847A Observations of the linear polarization of the sodium D-lines in the atmosphere of Mercury were made using a polarization analysis package with the Fabry-Perot interferometer at the Dunn Solar Telescope. The spectropolarimetric data resulting from these high-resolution images were subsequently confirmed using a comparable polarization package with the Solar Stellar Spectrograph at the McMath-Pierce Telescope. The observations are analogous to similar measurements of these lines in the Sun's atmosphere, where they constitute part of the `second solar spectrum'. Analysis of the data showed that the D1 line at 589 nm was depolarized, whereas the D2 line at 589.6 nm was polarized at the continuum level, consistent with Hanle-effect depolarization of the ground state and/or J-level quantum interference in the upper state. The discovery of similar behavior in the Hermean sodium D-lines suggests that the second solar spectrum is not unique to the Sun's atmosphere, but may be more pervasive. This work supported by NASA and the National Solar Observatory; the latter is operated by the Association of Universities for Research in Astronomy, Inc. under cooperative agreement with the National Science Foundation. Title: He I 1083nm Spectra of an Erupting Prominence Authors: Penn, M. J. Bibcode: 2002AAS...200.3713P Altcode: 2002BAAS...34..696P Observations were taken at the NSO/KP McMath/Pierce Telescope using a new 256x256 HgCdTe array camera as part of a collaboration between NSO and Cal State University Northridge. Spectra of the He I 1083nm line were taken between 17:36-18:06 UT on 22 Mar 2002 of the active region NOAA 9877 near the west limb. Doppler shifted flows of +/- 50 km/sec are seen near the active region sunspots. Line emission from an erupting prominence is also seen in these data above the west limb; rapid transverse motion as well as Doppler shifts of +/- 100 km/sec and greater are observed. Sample data and a more detailed analysis will be presented. Title: Infrared Spectroscopy from San Fernando Observatory: He I 1083 nm, O I 1316 nm, and Fe I 1565 nm Authors: Penn, M. J.; Ceja, J. A.; Bell, E.; Frye, G.; Linck, R. Bibcode: 2002SoPh..205...53P Altcode: Imaging spectroscopy of the Sun was carried out at the California State University Northridge San Fernando Observatory using an InGaAs near-IR video camera. Using the Si i 1082.71 nm and He i 1083.03 nm lines the Evershed effect is measured simultaneously in the photosphere and the chromosphere for three sunspots; the speed of the Evershed flow is measured to be between 3 to 8 times greater in the He i line than in the Si i line, and the direction is radially inward in the chromosphere and outward in the photosphere. Telluric absorption lines prevented a meaningful measurement of O i 1128.7 nm limb emission, but an upper limit of 20×10−3 B is measured for chromospheric limb emission at O i 1316.3 nm. Zeeman splitting in Fe i 1564.9 nm was observed in six sunspot umbrae, and a linear relationship between magnetic field and umbral continuum intensity is confirmed. Title: Status of CDMS search for dark matter WIMPs Authors: Cabrera, B.; Abusaidi, R.; Akerib, D. S.; Barnes, P. D.; Bauer, D. A.; Bolozdynya, A.; Brink, P. L.; Bunker, R.; Caldwell, D. O.; Castle, J. P.; Chang, C.; Clarke, R. M.; Colling, P.; Cristler, M. B.; Cummings, A.; da Silva, A.; Davies, A. K.; Dixon, R.; Dougherty, B. L.; Driscoll, D.; Eichblatt, S.; Emes, J.; Gaitskell, R. J.; Golwala, S. R.; Hale, D.; Haller, E. E.; Holmgren, D.; Hellmig, J.; Huber, M. E.; Irwin, K. D.; Jochum, J.; Lipschultz, F. P.; Lu, A.; Maloney, C.; Mandic, V.; Martinis, J. M.; Meunier, P.; Nam, S. W.; Nelson, H.; Neuhauser, B.; Penn, M. J.; Perera, T. A.; Perillo Isaac, M. C.; Pritychenko, B.; Ross, R. R.; Saab, T.; Sadoulet, B.; Sander, J.; Seitz, D. N.; Shestople, P.; Shutt, T.; Smith, A.; Smith, G. W.; Schnee, R. W.; Sonnenschein, A. H.; Spadafora, A. L.; Stockwell, W.; Taylor, J. D.; White, S.; Yellin, S.; Young, B. A. Bibcode: 2001AIPC..586..107C Altcode: 2001tsra.conf..107C We report on the latest results from the CDMS (cryogenic dark matter search) experiment. The experiment uses superconducting particle detectors, operated below 100 mK, to search for dark matter in the form of weakly interacting massive elementary particles or WIMPs. These detectors are either Si or Ge crystals, where the electron-hole production and the phonon production are measured for each event, allowing the discrimination of electron recoils (most backgrounds due to gammas and betas) from nuclear recoils (due to WIMPs and neutrons). We have recently reported new limits from the Stanford shallow site experiment (CDMS-I) which explore supersymmetric models where the lightest supersymmetric particle is often an excellent WIMP candidate. We will also report on the Soudan deep site facility for the CDMS-II experiment which is under construction, and on the status of the CDMS-II detector fabrication. . Title: Limits on the Wimp-Nucleon Cross-Section from the Cryogenic Dark Matter Search Authors: Schnee, R. W.; Abusaidi, R.; Akerib, D. S.; Barnes, P. D.; Bauer, D. A.; Bolozdynya, A.; Brink, P. L.; Bunker, R.; Cabrera, B.; Caldwell, D. O.; Castle, J. P.; Chang, C.; Clarke, R. M.; Colling, P.; Crisler, M. B.; Cummings, A.; da Silva, A.; Davies, A. K.; Dixon, R.; Dougherty, B. L.; Driscoll, D.; Eichblatt, S.; Emes, J.; Gaitskell, R. J.; Golwala, S. R.; Hale, D.; Haller, E. E.; Holmgren, D.; Hellmig, J.; Huber, M. E.; Irwin, K. D.; Jochum, J.; Lipschultz, F. P.; Lu, A.; Maloney, C.; Mandic, V.; Martinis, J. M.; Meunier, P.; Nam, S. W.; Nelson, H.; Neuhauser, B.; Penn, M. J.; Perera, T. A.; Isaac, M. C. Perillo; Pritychenko, B.; Ross, R. R.; Saab, T.; Sadoulet, B.; Sander, J.; Seitz, D. N.; Shestople, P.; Shutt, T.; Smith, A.; Smith, G. W.; Sonnenschein, A. H.; Spadafora, A. L.; Stockwell, W.; Taylor, J. D.; White, S.; Yellin, S.; Young, B. A. Bibcode: 2001cosm.conf...99S Altcode: The Cryogenic Dark Matter Search (CDMS) employs Ge and Si detectors to search for WIMPs via their elastic-scattering interactions with nuclei while discriminating against interactions of background particles. CDMS data, accounting for the neutron background, give limits on the spin-independent WIMP-nucleon elastic-scattering cross-section that exclude unexplored parameter space above 10 GeV c-2 WIMP mass and, at > 75% CL, the entire 3σ allowed region for the WIMP signal reported by the DAMA experiment. The move to a deep site in 2001 should improve the experiment's sensitivity by ~ 100X. Title: Helioseismic Holography and a Study of the Process of Magnetic Flux Disappearance in Canceling Bipoles Authors: Lindsey, Charles; Harvey, Karen L.; Braun, D.; Jones, H. P.; Penn, M.; Hassler, D. Bibcode: 2001STIN...0156300L Altcode: Project 1: We have developed and applied a technique of helioseismic holography along the lines of originally set out in our proposal. The result of the application of this diagnostic technique to solar activity and the quiet Sun has produced a number of important discoveries: (1) acoustic moats surrounding sunspots; (2) acoustic glories surround large active regions; (3) acoustic condensations beneath active regions; and (4) temporally-resolve acoustic images of a solar flare. These results have been published in a series of papers in the Astrophysical Journal. We think that helioseismic holography is now established as the most powerful and discriminating diagnostic in local helioseismology. Project 2: We conducted a collaborative observational program to define the physical character and magnetic geometry of canceling magnetic bipoles aimed at determining if the cancellation process is the result of submergence of magnetic fields. This assessment is based on ground-based observations combining photospheric and chromospheric magnetograms from NSO/KP, BBSO, and SOHO-MDI, and EUV and X-ray images from SOHO EIT/CDS, Yohkoh/SXT, and TRACE. Our study involves the analysis of data taken during three observing campaigns to define the height structure of canceling bipoles inferred from magnetic field and intensity images, and how this varies with time. We find that some canceling bipoles can be explained by the submerge of their magnetic flux. A paper on the results of this analysis will be presented at an upcoming scientific meeting and be written up for publication. Title: An Erupting Active Region Filament: Three-Dimensional Trajectory and Hydrogen Column Density Authors: Penn, M. J. Bibcode: 2000SoPh..197..313P Altcode: From 15:33 through 16:02 UT on 13 June 1998, observations of an erupting filament as it crossed solar disk center were obtained with the NSO/KPVT and SOHO/CDS instruments as part of the SOHO Joint Observing Program 70. Context observations show that this event was the eruption of the north-east section of a small active region filament associated with NOAA 8237, that the photospheric magnetic field was changing in this active region between 12-14 June 1998, and that a coronal Moreton-wave disk event occurred, as well as a white-light CME off the south-west solar limb. The NSO/KPVT imaging spectroscopy data covered 512 × 512 arc sec of the disk center and were spectrally centered at the He i 1083 nm line and captured ± 1.0 nm of surrounding solar spectrum. The He i absorption line is seen blue-shifted to velocities of between 200 and 300 km s−1. The true solar trajectory of the eruption is obtained by using the projected solar coordinates and by integrating the Doppler velocity. The filament travels with a total velocity of about 300 km s−1 along a path inclined roughly 49 deg to the solar surface and rises to a height of just over 1.5 solar radii before it becomes too diffuse to follow. The filament also shows internal motions with multiple Doppler components shifted by ± 25 km s−1. Finally, the KPVT data show no Stokes V profiles in the Doppler-shifted He i 1083.03 nm absorption to a limit of roughly 3×10−3 times the continuum intensity. The SOHO/CDS scanned the center of the KPVT FOV using seven EUV lines; Doppler-shifted filament emission is seen in lines from He i 58.4 nm, He ii 30.4 nm, O iv 55.5 nm, O v 63.0 nm, Ne vi 56.3 nm, and Mg x 61.0 nm representing temperatures from about 2×104K through 1×106K. Bound-free continuum absorption from H i, without confusion from foreground emission and line emission, is seen as the filament obscures underlying chromospheric emission. A fit to the wavelength dependence of the absorption from five lines between 55.5 to 63.0 nm yields a column density ξH I =4.8±2.5×1017 cm−2. Spatial maps show that this filament absorption is more confined than the regions which show emission. Title: A New Precise Measurement of the Coronal Magnetic Field Strength Authors: Lin, Haosheng; Penn, Matthew J.; Tomczyk, Steven Bibcode: 2000ApJ...541L..83L Altcode: Magnetism dominates the structure and dynamics of the solar corona. Current theories suggest that it may also be responsible for coronal heating. Despite the importance of the magnetic field in the physics of the corona and despite the tremendous progress made recently in the remote sensing of solar magnetic fields, reliable measurements of the coronal magnetic field strength and orientation do not exist. This is largely due to the weakness of coronal magnetic fields, previously estimated to be on the order of 10 G, and the difficulty associated with observing the extremely faint solar corona emission. Using a very sensitive infrared spectropolarimeter to observe the strong near-infrared coronal emission line Fe XIII λ10747 above active regions, we have succeeded in measuring the weak Stokes V circular polarization profiles resulting from the longitudinal Zeeman effect of the magnetic field of the solar corona. From these measurements, we infer field strengths of 10 and 33 G from two active regions at heights of h=0.12 Rsolar and h=0.15 Rsolar, respectively. We expect that this measurement technique will allow, in the near future, the routine precise measurement of the coronal magnetic field strength with application to many critical problems in solar coronal physics. Title: High-Resolution Spectra of Sodium in Mercury's Atmosphere Authors: Allen, J. E., Jr.; Penn, M. J.; Michael, B. P.; Branston, D. Bibcode: 2000DPS....32.2406A Altcode: 2000BAAS...32.1036A High-resolution (R ~100,000) spectral images of the sodium (Na) D1 and D2 lines in Mercury's atmosphere were obtained using a Fabry-Perot interferometer on the Dunn Solar Telescope at Sacramento Peak, NM. Observations were made from May 29 to June 4, 2000 when Mercury was at ~20.5 and 23.2 degrees E elongation with a radial velocity of ~-34.9 and -33.2 km/s, respectively. Preliminary analysis of the data suggests the atmosphere was optically thicker than when these emissions were first observed (Potter and Morgan 1985). This is attributed to the fact that those observations were made close to solar minimum, whereas our measurements were made closer to solar maximum. The observed D1 and D2 emission lines were blue shifted by ~0.74 and 0.71 Å, respectively, corresponding to Doppler shifts of ~-37.65 and -36.29 km/s.

Potter, A. E. and Morgan, T. H. 1985, Science 229, 651. Title: Exclusion Limits on the WIMP-Nucleon Cross Section from the Cryogenic Dark Matter Search Authors: Abusaidi, R.; Akerib, D. S.; Barnes, P. D.; Bauer, D. A.; Bolozdynya, A.; Brink, P. L.; Bunker, R.; Cabrera, B.; Caldwell, D. O.; Castle, J. P.; Clarke, R. M.; Colling, P.; Crisler, M. B.; Cummings, A.; da Silva, A.; Davies, A. K.; Dixon, R.; Dougherty, B. L.; Driscoll, D.; Eichblatt, S.; Emes, J.; Gaitskell, R. J.; Golwala, S. R.; Hale, D.; Haller, E. E.; Hellmig, J.; Huber, M. E.; Irwin, K. D.; Jochum, J.; Lipschultz, F. P.; Lu, A.; Mandic, V.; Martinis, J. M.; Nam, S. W.; Nelson, H.; Neuhauser, B.; Penn, M. J.; Perera, T. A.; Perillo Isaac, M. C.; Pritychenko, B.; Ross, R. R.; Saab, T.; Sadoulet, B.; Schnee, R. W.; Seitz, D. N.; Shestople, P.; Shutt, T.; Smith, A.; Smith, G. W.; Sonnenschein, A. H.; Spadafora, A. L.; Stockwell, W.; Taylor, J. D.; White, S.; Yellin, S.; Young, B. A. Bibcode: 2000PhRvL..84.5699A Altcode: 2000astro.ph..2471C The Cryogenic Dark Matter Search (CDMS) employs Ge and Si detectors to search for weakly interacting massive particles (WIMPs) via their elastic-scattering interactions with nuclei while discriminating against interactions of background particles. CDMS data, accounting for the neutron background, give limits on the spin-independent WIMP-nucleon elastic-scattering cross section that exclude unexplored parameter space above 10 GeV/c2 WIMP mass and, at >75% C.L., the entire 3σ allowed region for the WIMP signal reported by the DAMA experiment. Title: An Erupting Active Region Filament: Three-Dimensional Trajectory and Hydrogen Column Density Authors: Penn, M. J. Bibcode: 2000SPD....31.0268P Altcode: 2000BAAS...32..823P From 15:33-16:02 UT on 13 June 1998 observations of an erupting filament as it crossed solar disk center were obtained with the NSO/KPVT and SoHO/CDS instruments as part of the SoHO Joint Observing Program 70. Context observations show that this event was the eruption of the north-east section of a small active region filament associated with NOAA 8237, that the photospheric magnetic field was changing in this active region from 12 through 14 June 1998, that a coronal Moreton-wave disk event occurred, as well as a white-light CME off the south-west solar limb. The NSO/KPVT imaging spectroscopy sho the He I 1083 nm absorption line blue-shifted to velocities of between 200 and 300 km s-1. The true solar trajectory of the eruption is obtained by using the projected solar coordinates and by integrating the Doppler velocity. The filament travels with a total velocity of about 300 km s-1 along a path inclined roughly 49 degrees to the solar surface and rises to a height of just over 1.5 solar radii. The KPVT data show no Stokes V profiles in the Doppler shifted He I 1083 nm absorption to a limit of roughly 3 x 10-3 times the continuum intensity. The SoHO/CDS data scanned the center of the KPVT FOV using seven EUV lines; Doppler shifted filament emission is seen in six lines from representing temperatures from about 2 x 104K through 1 x 106K. Bound-free continuum absorption from H I, free from confusion from foreground emission and line emission, is seen as the filament obscures underlying chromospheric emission. A fit to the wavelength dependence of the absorption from five lines between 55.5 to 63.0 nm yields a column density ξ HI = 1.7 x 1018cm-2. Spatial maps show that this filament absorption is more confined than the regions which show emission. This work was made possible by 1997 and 1999 SoHO Guest Investigator awards NASA #W-19,142 Basic and NASA NAG5-8004. Title: Does Magnetic Flux Submerge at Flux Cancelation Sites? Authors: Harvey, Karen L.; Jones, Harrison P.; Schrijver, Carolus J.; Penn, Matthew J. Bibcode: 1999SoPh..190...35H Altcode: Simultaneous measurements of the magnetic fields in the photosphere and chromosphere were used to investigate if magnetic flux is submerging at sites between adjacent opposite polarity magnetic network elements in which the flux is observed to decrease or `cancel'. These data were compared with chromospheric and coronal intensity images to establish the timing of the emission structures associated with these magnetic structures as a function of height. We found that most of the cancelation sites show either that the bipole is observed longer in the photosphere than in the chromosphere and corona (44%) or that the timing difference of the disappearance of the bipole between these levels of the atmosphere is unresolved. The magnetic axis lengths of the structures associated with the cancelation sites are on average slightly smaller in the chromosphere than the photosphere. These observations suggest that magnetic flux is retracting below the surface for most, if not all, of the cancelation sites studied. Title: Comparison of Fe λ5303, λ6374 and λ7892 spectral line observations in a coronal hole and streamer Authors: Wood, Christine H.; Habbal, Shadia R.; Esser, Ruth; Penn, Matthew Bibcode: 1999AIPC..471..293W Altcode: 1999sowi.conf..293W We present intensity and line width measurements of the Fe X λ6374, Fe XI λ7892 and Fe XIV λ5303 lines between 1.03 and 1.4 Rs in a coronal hole and a streamer. The observations were made at the National Solar Observatory at Sacramento Peak on 26 February 1998. In the coronal hole, only the Fe X line was observed; an upper limit of 106 K for the electron temperature and 28 km/s for the amplitude of nonthermal motions was inferred from the Fe X measurements at 1.06 Rs. While all three lines were observed in the streamer, the unique result was that the width of the Fe XI line increased with heliocentric distance as opposed to a decrease in the Fe X and Fe XIV line widths. We interpret this as evidence for the existence of multitemperature static plasmas, and a solar wind outflow at the streamer base. Title: New Measurements of the Solar Limb Emission in the O I 777.4 and 844.6 Nanometer Lines Authors: Penn, M. J. Bibcode: 1999ApJ...518L.131P Altcode: Slit spectra of the solar limb emission in the 777.4 and 844.6 nm O I lines are calibrated against the solar disk center brightness. Data from CCD spectrograph instruments at two different observatories show limb emission with identical line intensities and measure a value of R4≡ΣI(844.6 nm)/ΣI(777.4 nm)=0.20+/-0.02, very different from the ratios computed from early photographic measurements of these lines. Implied by this new value of R4 is that O I lines in the solar chromosphere are formed in regions with electron densities log(Ne)>11.5 and that collisional excitation is more important than the photoexcitation by accidental resonance mechanism. Title: Disk Center Eruptive Filament Line Profile Observations Authors: Penn, M. J. Bibcode: 1999AAS...19410106P Altcode: 1999BAAS...31..999P From 15:33-15:54 UT on 13 June 1998 observations of an erupting filament at disk center were obtained with the NSO/KPVT, SoHO/CDS, and TRACE instruments as part of the SoHO Joint Observing Program 70. The NSO/KPVT imaging spectroscopy data scanned 512x512 arcsec of the solar surface at disk center and were spectrally centered at the He I 1083 nm line and captured +/- 1.0 nm of surrounding solar spectrum. The He I absorption line is seen blue-shifted to velocities of between 200 and 300 km/sec. The true solar trajectory of the eruption is obtained by using the projected solar N/S and E/W coordinates and by integrating the Doppler velocity. The filament travels along a path inclined roughly 45 degrees to the solar surface to a height of about 1.5 solar radii before it becomes too diffuse to follow. The filament also shows internal motions (untwisting?) with multiple Doppler components shifted by +/- 25 km/sec. The SoHO/CDS data scanned the region in seven EUV lines; results from these data will also be presented. Finally, the TRACE data shows the morphology of the eruption in the EUV lines of Fe IX and Fe XII. Evolution of the hot coronal plasma is evident, and evolving dark regions seem to show the cool plasma transverse motions. The NSO/KPVT data presented are produced cooperatively by NSF/NOAO, NASA/GSFC and NOAA/SEL. This work is is part of a 1997 and a 1999 SoHO Guest Investigator award. Title: Preliminary limits on the WIMP-nucleon cross section from the cryogenic dark matter search (CDMS). Authors: Akerib, D. S.; Barnes, P. D., Jr.; Bauer, D. A.; Brink, P. L.; Cabrera, B.; Caldwell, D. O.; Clarke, R. M.; da Silva, A.; Davies, A. K.; Dougherty, B. L.; Irwin, K. D.; Gaitskell, R. J.; Golwala, S. R.; Haller, E. E.; Jochum, J.; Knowlton, W. B.; Kuzminov, V.; Nam, S. W.; Novikov, V.; Penn, M. J.; Perera, T. A.; Ross, R. R.; Sadoulet, B.; Schnee, R. W.; Shutt, T.; Smith, A.; Sonnenschein, A. H.; Spadafora, A. L.; Stockwell, W. K.; Yellin, S.; Young, B. A. Bibcode: 1999NuPhS..70...64A Altcode: 1997astro.ph.12343A The authors are conducting an experiment to search for WIMPs, or weakly-interacting massive particles, in the galactic halo using terrestrial detectors. This generic class of hypothetical particles, whose properties are similar to those predicted by extensions of the standard model of particle physics, could comprise the cold component of non-baryonic dark matter. The authors describe the experiment, which is based on cooled germanium and silicon detectors in a shielded low-background cryostat. The detectors achieve a high degree of background rejection through the simultaneous measurement of the energy in phonons and ionization. Using exposures on the order of one kilogram-day from initial runs of the experiment, the authors have achieved (preliminary) upper limits on the WIMP-nucleon cross section that are comparable to much longer runs of other experiments. Title: Results of the Cryogenic Dark Matter Search (CDMS) Obtained with Thermistor-Instrumented Germanium Calorimeters Authors: Sonnenschein, A.; Bauer, D. A.; Caldwell, D. O.; Nelson, H.; Yellin, S.; Brink, P. L.; Cabrera, B.; Clarke, R. M.; Colling, P.; Davies, A. K.; Irwin, K. D.; Nam, S. W.; Penn, M. J.; Akerib, D. S.; Bolodyaynya, A.; Perera, T. A.; Schnee, R. W.; Crisler, M. B.; Dixon, R.; Eichblatt, S.; da Silva, A.; Gaitskell, R. J.; Golwala, S. R.; Jochum, J.; Barnes, P. D., Jr.; Sadoulet, B.; Shutt, T.; Spadafora, A. L.; Stockwell, W. K.; Haller, E. E.; Knowlton, W. B.; Ross, R. R.; Smith, A.; Smith, G.; Young, B. A.; Neuhausser, B.; Lipschultz, F. Bibcode: 1999idm..conf..347S Altcode: No abstract at ADS Title: Results and status of the Cryogenic Dark Matter Search (CDMS). Authors: Schnee, R. W.; Akerib, D. S.; Barnes, P. D., Jr.; Bauer, D. A.; Brink, P. L.; Cabrera, B.; Caldwell, D. O.; Clarke, R. M.; Colling, P.; Crisler, M. B.; Dasilva, A.; Davies, A. K.; Dougherty, B. L.; Eichblatt, S.; Irwin, K. D.; Gaitskell, R. J.; Golwala, S. R.; Haller, E. E.; Jochum, J.; Knowlton, W. B.; Kuzminov, V.; Nam, S. W.; Novikov, V.; Penn, M. J.; Perera, T. A.; Ross, R. R.; Sadoulet, B.; Shutt, T.; Smith, A.; Sonnenschein, A. H.; Spadafora, A. L.; Stockwell, W. K.; Yellin, S.; Young, B. A. Bibcode: 1998PhR...307..283S Altcode: The Cryogenic Dark Matter Search experiment uses cooled germanium and silicon detectors for a direct search for weakly interacting massive particles in our Galaxy. The novel detectors allow a high degree of background rejection by discriminating between electron and nuclear recoils through the simultaneous measurement of the energy deposited in phonons and ionization. Exposures on the order of one kilogram-day from initial runs of our experiment yield (preliminary) upper limits on the WIMP-nucleon cross section that are comparable to much longer runs of other experiments. Current and future runs promise significant improvement, primarily due to improved detectors and reduced surface-electron backgrounds. Title: Limits on the WIMP-Nucleon Cross Section from the Cryogenic Dark Matter Search Authors: Akerib, D. S.; Barnes, P. D., Jr.; Bauer, D. A.; Bolozdynya, A.; Cabrera, B.; Caldwell, D. O.; Clarke, R. M.; Crisler, M.; da Silva, A.; Davies, A. K.; Dixon, R.; Eichblatt, S.; Irwin, K. D.; Gaitskell, R. J.; Golwala, S. R.; Haller, E. E.; Jochum, J.; Kuzminov, V.; Kurylowicz, M.; Nam, S. W.; Penn, M. J.; Perera, T. A.; Ross, R. R.; Saab, T.; Sadoulet, B.; Schnee, R. W.; Seitz, D.; Shutt, T.; Smith, A.; Sonnenschein, A. H.; Spadafora, A. L.; White, S.; Yellin, S.; Young, B. A. Bibcode: 1998tx19.confE.271A Altcode: The Cryogenic Dark Matter Search (CDMS) aims to detect WIMPs in the galactic halo by observation of elastic scattering interactions with nuclei in germanium and silicon targets. CDMS uses novel cryogenic detectors that actively reject typical radioactive backgrounds, and thus is ultimately vastly more sensitive to WIMP interactions than previous experiments. We present limits on the WIMP-nucleon elastic scattering cross section based on data acquired during recent runs, reflecting significant detector and background improvements. Title: Constraints on the Presence of WIMPs in the Galactic Halo from the Cryogenic Dark Matter Search Authors: Golwala, S. R.; Dasilva, A.; Gaitskell, R. J.; Hellmig, J.; Jochum, J.; Seitz, D.; Smith, G.; Spadafora, A. L.; White, S.; Perillo Isaac, M. C.; Ross, R. R.; Sadoulet, B.; Akerib, D. S.; Bolozdynya, A.; Perera, T. A.; Schnee, R. W.; Barnes, P. D.; Bauer, D. A.; Bunker, R.; Caldwell, D. O.; Nelson, H. N.; Sonnenschein, A. H.; Yellin, S.; Brink, P. L.; Cabrera, B.; Clarke, R. M.; Colling, P.; Davies, A. K.; Kurylowicz, M.; Nam, S. W.; Penn, M. J.; Saab, T.; Castle, P.; Drury, L. O'C; Lipschultz, F. P.; Neuhauser, B. J.; Crisler, M.; Dixon, R.; Eichblatt, S.; Haller, E. E.; Kuzminov, V.; Martinis, J.; Irwin, K. D.; Shutt, T.; Smith, A.; Young, B. A.; CDMS Collaboration Bibcode: 1998AAS...193.6105G Altcode: 1998BAAS...30Q1337G The Cryogenic Dark Matter Search (CDMS) aims to detect WIMPs in the galactic halo by observation of elastic scattering interactions with nuclei in germanium and silicon targets. CDMS uses novel cryogenic detectors that actively reject typical radioactive backgrounds, and thus is ultimately vastly more sensitive to WIMP interactions than previous experiments. We present limits on the WIMP-nucleon elastic scattering cross section based on data acquired during recent runs, reflecting significant detector and background improvements. Title: The Helium Spectrum in the Quiet Sun: The January 16/17 and May 7-13 1997 Coordinated SOHO/Ground-Based Observational Campaigns Authors: Andretta, Vincenzo; Jordan, Stuart D.; Muglach, Karin; Garcia, Adriana; Jones, Harrison P.; Penn, Matthew J.; Soltau, Dirk Bibcode: 1998ASPC..155..336A Altcode: 1998sasp.conf..336A No abstract at ADS Title: Synoptic Coronal Temperature; Magnetic Field and He 11083 NM Observations Authors: Penn, M.; Altrock, R. C.; Henry, T.; Guhathakurta, M. Bibcode: 1998ASPC..140..325P Altcode: 1998ssp..conf..325P No abstract at ADS Title: Electron Temperature Distribution in Coronal Holes Authors: Halas, C. D.; Habbal, S. R.; Penn, M.; Uitenbroek, H.; Esser, R.; Altrock, R.; Guhathakurta, M. Bibcode: 1997AAS...191.7413H Altcode: 1997BAAS...29Q1326H Knowledge of the electron temperature within coronal holes is extremely important for constructing solar wind models and for understanding the coronal heating process. We report on the two-dimensional CCD observations of the Fe IX 4585, Fe X 6374, Fe XI 7892 and Fe XIV 5303 { Angstroms} emission lines made using a coronagraph at the National Solar Observatory at Sacramento Peak. These iron lines, which have a peak formation temperature of 5 10(5) , 10(6) , 1.2 10(6) , and 2 10(6) K, respectively, allow the examination of different temperature plasmas within the same large scale magnetic structure. To account for possible line of sight ambiguities from hot material in the foreground or background of the coronal hole, Yohkoh data were used to determine the extent of the coronal hole along the line of sight. Intensities and widths of these spectral lines as a function of heliocentric distance out to 1.15 R_s will be presented. A comparison will be made between coronal hole and streamer observations. Title: Comparison of NSO/KPVT 1083 NM and SOHO/CDS/SUMER Observations of a Coronal Hole. Authors: Jones, H. P.; Andretta, V.; Jordan, S. D.; Penn, M. J. Bibcode: 1997AAS...191.7304J Altcode: 1997BAAS...29.1321J As part of SOHO Joint Observing Program 16 to study the solar formation of Helium, coordinated observations of a coronal hole were obtained on 17 Jan 97. In this paper, we compare the NSO/KPVT full-disk 1083 nm spectroheliogram and a time sequence of spectra-spectroheliograms of the coronal hole near the south solar pole with approximately cospatial and cotemporal SOHO spatial-spectral data taken in He I (58.4 nm, CDS and SUMER) and He II 30.4 nm (CDS) together with several transition-region and coronal lines of CIII, OIII, OIV, MgIX, MgX, SiIX, and SiXII. We have previously reported on correlations of line intensities. Here we concentrate as well on Doppler shifts and, in particular, line asymmetry in the He I 1083 nm line which shows augmented absorption in the blue wing of the line within the coronal hole in the same sense as reported by Dupree, Penn, and Jones (1996, ApJ 467, L121). Title: H i 1083 NM Oscillations and Downflows Near the North Solar Pole Authors: Penn, M. J.; Allen, C. L. Bibcode: 1997SoPh..174..359P Altcode: Imaging spectroscopic data of the Sii 1082.7 nm (photospheric) and Hei 1083.0 nm (chromospheric) spectral lines were taken starting 22:05 UT on 23 July, 1996 with the NASA/NSO Spectromagnetograph at the NSO/Kitt Peak Vacuum Telescope. Observations were made near the north solar pole, with a field of view of 100 by 400 arc sec and with a temporal cadence of 53 s for 2 hr. Simple fitting to the line profiles measured the line position, depth, and spectral full-width at half-maximum. Power spectra of the velocity oscillations in each line were computed, and the oscillation power in the 2 to 6 mHz frequency band versus view angle was measured to search for horizontal oscillations. Horizontal waves are not detected to limiting amplitudes (1σ) of 22 m s-1 in the chromosphere and 9 m s-1 in the photosphere. These values are used to estimate limits for the energy flux into the corona. The amplitude of radial oscillations in the chromosphere is twice that of the photosphere. No statistically meaningful oscillation power is measured in the spectral parameters of the Hei line in the emission shell seen above the continuum limb. Finally, rapidly evolving red-shift events are observed in the Hei 1083 nm line on the disk; these events are some sort of coronal rain, and there are about 40 of these events on the solar disk at any moment. Title: Polarized Resonance Fluorescence of Comet Hale-Bopp Authors: Allen, J. E., Jr.; Penn, M. J.; Branston, D.; Disanti, M. A. Bibcode: 1997DPS....29.3719A Altcode: 1997BAAS...29.1050A Because it is basically a vector-related technique, polarization spectroscopy can provide information not obtainable using traditional spectroscopic methods. Typically polarization measurements are assoc- iated with the characterization of the dust continuum. However, although not as frequently studied, resonance fluorescence can also exhibit polarization and the information can be related to physical properties of the comet, e.g., magnetic-field direction. Observations of comet Hale-Bopp were made shortly after perihelion (April 4 - 14, 1996) using the Vacuum Tower Telescope at the National Solar Observatory in Sunspot, NM. Images were taken through a variety of filters and spectra acquired using the high-resolution horizontal spectrograph; in both cases data were acquired with and without polarization analysis. Here we report on the preliminary analysis of polarization images and spectra of the sodium (Na) D1 and D2 lines and the Swan system of C2. Title: The Height and Temporal Structure of X-Ray Bright Points Authors: Harvey, K. L.; Penn, M.; Tarbell, T.; Saba, J.; Hassler, D.; Moses, J. D.; Fludra, A. Bibcode: 1997SPD....28.0124H Altcode: 1997BAAS...29..883H On April 12, 1996, several ground-based observatories, the Yohkoh/SXT and the SOHO/MDI, EIT, SUMER, and CDS instruments participated in a collaborative study of X-Ray Bright Points (XBPs). During a several hour period, simultaneous images were obtained of an area centered at N10E00. At NSO/KP, observations were made of the HeI 1083 nm line profile from which we have derived the intensity at line center, equivalent width, and the velocity at every 1 pixel (1.15 arc-seconds) within an 8 x 8 arc-minute area. Our paper will present the results of a comparison, spatially and temporally, of these data with changes in the magnetic field observed by the MDI, intensities and velocities observed with SUMER and CDS, and the intensity images observed by the SXT and EIT. We will use this ensemble of intensity, magnetic and velocity field images to derive the height structure of XBPS, its variation as a function of time and relation to the associated magnetic field configuration. Title: Quiet Sun He I 1083 NM Chromospheric Events Authors: Penn, M. J.; Jones, H. P. Bibcode: 1997SPD....28.1303P Altcode: 1997BAAS...29..917P Several types of flows are observed in the quiet solar chromosphere using the He I 1083 nm absorption line with data from the NSO/KPVT. Downflow events, termed ``He Rain'' are described by about 4 km/sec Doppler red-shift of the line, an increased line width, and enhanced line absorption. The ``He Rain'' events begin with a small, compact morphology then evolve during 500 seconds to become extended and diffuse. The birth-rate of these ``He Rain'' events suggests an association with either coronal loop interactions or macrospicules. Loop-flow events observed with the He I 1083 nm line show blue-shifts followed by a red-shift, an increased line width and enhanced line absorption. The events follow curving trajectories with sizes about 30 arcsec. These events occur much less frequently than spicules, but may be associated with a type of spicule or some flow along the local magnetic field. Recent observations of these quiet Sun events and discussion of the associated coronal events will be presented. Title: Reduction and Analysis of He I 1083 NM Spectra-Spectroheliograms Authors: Jones, H. P.; Winters, W. F.; Penn, M. J.; Schwitters, J. D. Bibcode: 1997SPD....28.0225J Altcode: 1997BAAS...29..897J Over two decades of synoptic 1083 nm data from the National Solar Observatory/Kitt Peak Vacuum Telescope (NSO/KPVT) attest to the fact that satisfactory equivalent width images may be obtained from simple sums over ``line''and ``continuum'' bandpasses. However, much more care is needed to extract Doppler velocity, line depth, and asymmetry since the 1083 nm line typically has line depths of only a few percent and is blended with both telluric water vapor and the red wing of a nearby Si I line at 1082.8 nm. We present a new algorithm for analysis of He I 1083 nm data obtained with the NASA/NSO Spectromagnetograph (SPM) at the KPVT. A linear fit to intensity averages over bands near 1082.4 nm and 1083.6 nm specifies the continuum intensity across the wavelength domain of interest. The spectral algorithm currently used for 868.8 nm SPM magnetograms computes line-center wavelengths and depths for the strong adjacent telluric and Si lines. Quick fits of the damping wings of these features together with a scaled profile of the weak water vapor feature which is coincident in wavelength with the 1083 nm line (Breckenridge and Hall, 1973: Solar Phys. 28, 15) are removed from the spectral region containing the 1083 nm line. The spectral algorithm then computes the central wavelength and line depth of the 1083 nm line. An extension of this algorithm locates the bisector at the 0.35 central line-depth position on the profile to compute a line asymmetry parameter (Dupree, Penn, and Jones, 1976: ApJ 467, L121). We show sample results of the algorithm applied both off-line to spectra-spectroheliograms and on-line to spatial-spectral data as they are acquired. Title: Investigating the Formation of the Helium Spectrum with Coordinated SOHO/Kitt Peak/Sacramento Peak Observations Authors: Andretta, V.; Jordan, Stuart D.; Jones, Harrison P.; Penn, Matthew J. Bibcode: 1997ESASP.404..163A Altcode: 1997cswn.conf..163A No abstract at ADS Title: Looking for WIMPs: The Cryogenic Dark Matter Search Authors: Jochum, J.; Barnes, P. D., Jr.; Dasilva, A.; Emes, J.; Gaitskell, R. J.; Golwala, S. R.; Haller, E. E.; Ross, R. R.; Sadoulet, B.; Seitz, D.; Shutt, T.; Smith, G.; Stockwell, W.; Taylor, J.; Therrien, R.; White, S.; Brink, P.; Cabrera, B.; Clarke, R.; Davies, A.; Dougherty, B. L.; Hennesy, M.; Irwin, K. D.; Nam, S.; Penn, M. J.; Akerib, D.; Perera, T. A.; Schnee, R. W.; Young, B. A.; Bauer, D.; Caldwell, D. O.; Hale, D.; Sonnenachein, A.; Yellin, S.; Novikov, K.; Kusminov, V. Bibcode: 1997dmap.conf..445J Altcode: No abstract at ADS Title: Quiet Sun HEL 1083 NM Chromospheric Flows Authors: Penn, M. J. Bibcode: 1997ESASP.404..583P Altcode: 1997cswn.conf..583P No abstract at ADS Title: Progress of the Cryogenic Dark Matter Search (CDMS) experiment Authors: Shutt, T.; Akerib, D. S.; Barnes, P. D., Jr.; Bauer, D.; Brink, P.; Cabrera, B.; Caldwell, D. O.; Chugg, B.; Clarke, R. M.; Dasilva, A.; Davies, A.; Dougherty, B. L.; Emes, J.; Gaitskell, R. J.; Golwala, S. R.; Hale, D.; Haller, E. E.; Irwin, K. D.; Knowlton, W. B.; Kuzminov, V.; Lu, A.; Muno, M.; Nam, S. W.; Novikov, V.; Penn, M. J.; Ross, R. R.; Sadoulet, B.; Seitz, D.; Smith, A.; Smith, G.; Sonnenschein, A.; Stockwell, W.; Taylor, J. D.; Therrien, R.; Trumbull, T. L.; White, S.; Yellin, S.; Young, B. A. Bibcode: 1996NuPhS..51..318S Altcode: We report on progress of the CDMS experiment, which seeks to detect WIMP dark matter through its interactions in a particle detector operated in a low radioactivity environment. We have developed novel cryogenic detectors which discriminate between nuclear recoils from WIMPs and electron recoils from background photons. We describe the experiment and discuss recent progress, including first operation of a cryogenic detector in the low radioactivity cryostat in June of 1996. Title: Limb Observations of HE I 1083 NM Authors: Penn, M. J.; Jones, H. P. Bibcode: 1996SoPh..168...19P Altcode: Imaging spectroscopic data of the He I 1083 nm limb emission were taken on several dates in October and November 1995 with the NASA/NSO spectromagnetograph at the NSO/Kitt Peak vacuum telescope and on 9 December, 1993 with the Michigan infrared camera at the NSO/Sacramento Peak vacuum tower telescope. Emission line profiles were observed in quiet-Sun and coronal hole locations on the northern and southern solar poles and on the east solar limb. The height of the He I 1083 nm shell above the continuum limb at 1083 nm was measured to be 2.11 ± 0.12 Mm with the Kitt Peak data, and 1.74 ± 0.05 Mm with the Sacramento Peak data. The Kitt Peak data show (1) within the measurement error there is no significant difference in the height or thickness of the emission shell in coronal holes compared with the quiet Sun, (2) the 1083 nm emission intensity drops by 50% in coronal holes, (3) the line width decreases by about 2 km s-1 in coronal holes (suggesting less inclined spicules), (4) the line width of the He I 1083 nm line jumps significantly as the line of sight crosses the solar limb (consistent with a higher temperature upper shell), (5) a quiescent prominence shows a smaller spectral line width (consistent with a cooler temperature or less velocity broadening), and (6) the entire emission shell and the prominence show a He I spectral component ratio of about 8 (suggesting optically thin emission). Title: He i 10830 Angstrom Wing Asymmetry in Polar Coronal Holes: Evidence for Radial Outflows Authors: Dupree, A. K.; Penn, M. J.; Jones, H. P. Bibcode: 1996ApJ...467L.121D Altcode: Imaging spectroscopy of the Sun, carried out across the the solar poles, yielded several thousand profiles of the He I 10830 A chromospheric absorption line with effective spatial pixels of 1.1 x 2 arcsec2. Profiles of He I 10830 A show the relative blue-wing absorption is stronger in the coronal holes than in the quiet Sun, creating an asymmetric profile indicative of mass outflow. Within the coronal holes, blueshifted line wings are found where He I absorption is weak, corresponding to the center of supergranular cells. However, in the quiet Sun, there is no line wing shift in supergranular centers. Spatially compact regions of strong red-wing absorption also occur across the disk. Within the polar coronal holes, the amplitude of the wing shift shows a linear dependence with cos theta (where the angle theta is measured with respect to an outward normal to the Sun's surface), suggesting that a radial outflow occurs with a characteristic speed of ~8 km s-1. These observations represent the first detection of systematic outflows near the chromosphere transition region interface that appear to mark the origin of the high-speed wind acceleration from the solar surface. Title: He I 10830 Angstroms Polarimetry of Filament Authors: Lin, H.; Kuhn, J. R.; Penn, M. Bibcode: 1996AAS...188.8001L Altcode: 1996BAAS...28..956L Full Stokes parameters (IQUV) were obtained from a filament at the He I 10830 Angstroms wavelength. These observations provide information on the vector magnetic field configuration of the filaments, which, up-to-date, were mostly infered from indirect observations like the photospheric magnetograms and Hα images. We will present the instrumentation, as well as the magnetic field configuration of the filament derived from these data, and discuss their implications to filament models. Title: Limb Observations of He I 1083nm Authors: Penn, M.; Jones, H. Bibcode: 1996AAS...188.7906P Altcode: 1996BAAS...28..956P Imaging spectroscopic data of the He I 1083 nm limb emission were taken on several dates in Oct and Nov 1995 with the NASA/NSO Spectromagnetograph at the NSO/Kitt Peak Vacuum Telescope and on 09 Dec 1993 with the Michigan Infrared Camera at the NSO/Sac Peak Vacuum Tower Telescope. Emission line profiles were observed in quiet Sun and coronal hole locations on the northern and southern solar poles and on the east solar limb. The height of the He I 1083 nm shell above the continuum limb at 1083 nm was measured to be 2.11+/-0.12 Mm with the Kitt Peak data, and 1.74+/-0.05 Mm with the Sac Peak data. The Kitt Peak data show (1) within the measurement error there is no significant difference in the height or thickness of the emission shell in coronal holes compared with the quiet Sun, (2) the 1083 nm emission intensity drops by 50% in coronal holes, (3) the line width decreases by about 2 km s(-1) in coronal holes (suggesting less inclined spicules), (4) the line width of the He I 1083 nm line jumps significantly as the line-of-sight crosses the solar limb (consistent with a higher temperature upper shell), (5) a quiescent prominence shows a smaller spectral line width (consistent with a cooler temperature or less velocity broadening), and (6) the entire emission shell and the prominence show a He I spectral component ratio of about 8 (suggesting optically thin emission). Title: Installation of the Cryogenic Dark Matter Search (CDMS) Authors: Barnes, P. D.; da Silva, A.; Akerib, D. S.; Bauer, D.; Brink, P.; Cabrera, B.; Caldwell, D. O.; Chugg, B.; Clarke, R. M.; Cummings, A.; Davies, A.; Diaz, R. C.; Dougherty, B. L.; Emes, J.; Golwala, S. R.; Hale, D.; Haller, E. E.; Irwin, K. D.; Knowlton, W. B.; Kuziminov, V.; Lu, A.; Nam, S. W.; Penn, M. J.; Novikov, V.; Pritychenko, B. V.; Quéinnec, F.; Ross, R. R.; Sadoulet, B.; Seitz, D.; Shutt, T.; Smith, A.; Smith, G.; Sonnenschein, A.; Stockwell, W.; Taylor, J. D.; Therrien, R.; Trumbull, T. L.; White, S.; Wolgast, R. C.; Yellin, S.; Young, B. A. Bibcode: 1996NIMPA.370..233B Altcode: We discuss the status of a cryogenic dark matter search beginning operation in the Standard Underground Facility. The detectors will be cooled in a specially designed cryostat connected to a modified side access Oxford 400 dilution refrigerator. We discuss two detector designs and performance, the cryostat construction and operation, and the multi-level shield surrounding the cryostat. Finally, we will examine the limits which we will be able to set on WIMP dark matter with this experiment. Title: The Near-Infrared Coronal Spectrum Authors: Kuhn, J. R.; Penn, M. J.; Mann, I. Bibcode: 1996ApJ...456L..67K Altcode: Sensitive measurements of the near-infrared coronal spectrum were obtained from the 1994 total solar eclipse. A new [S IX] emission line at 1.25249 +/- 0.00003 mu m has been detected, and a bright, potentially important diagnostic, [Si X] line at 1.43 mu m has been confirmed. Upper limits on the intensity of several other predicted IR emission lines have been established. Also, diffuse He I emission, perhaps geocoronal, has been observed with a significant heliocentric redshift. Title: Infrared Spectroscopic Observations of Neutral Helium during the 1994 Eclipse Authors: Mann, I.; Kuhn, J. R.; Penn, M. J. Bibcode: 1996ASPC..104..345M Altcode: 1996pcdi.conf..345M; 1996IAUCo.150..345M No abstract at ADS Title: Mapping Prominence Magnetic Fields: New He I 1083 nm Data Authors: Penn, M.; Kuhn, J. Bibcode: 1995SPD....26..618P Altcode: 1995BAAS...27..965P No abstract at ADS Title: Imaging Spectropolarimetry of the He i 1083 Nanometer Line in a Flaring Solar Active Region Authors: Penn, M. J.; Kuhn, J. R. Bibcode: 1995ApJ...441L..51P Altcode: Slit spectra, simultaneously measuring left and right circular polarization of the solar spectrum at 1082.9 +/- 0.4 nm, were taken using the National Solar Observatory (NSO) Vacuum Tower Telescope (VTT) at Sacramento Peak with a 128 x 128 pixel HgCdTe IR camera. By moving the slit the solar active region NOAA 7629 was scanned with a cadence of 246 s from 1724 to 1902 UT on 1993 December 6. The region was in the decay phase of a C9.7 flare. Intensity, velocity and longitudinal magnetic field in both the Si I (photospheric) and He I (chromospheric) lines are computed from fits to the line profiles in left and right polarizations. Analysis of these quantities show: (1) He I line emission in three decaying flare kernels, (2) Zeeman splitting of the He I emission measuring the longitudinal magnetic field inside the flare kernels; (3) dark He I active region filaments avoid strong longitudinal chromospheric magnetic field, and an active filament (with a transverse speed of 9 km/s) produces fluctuations in the strength of the longitudinal magnetic fields, and (4) bipolar moving magnetic features (MMFs) and emerging active region bipoles (EARBs) are observed at photospheric but not chromospheric heights. Title: The Near Infrared Coronal Spectrum: Results from the 1994 Eclipse Authors: Kuhn, J.; Penn, M.; Mann, I. Bibcode: 1995SPD....26..609K Altcode: 1995BAAS...27..963K No abstract at ADS Title: Infrared tools for solar astrophysics: What's next? Authors: Kuhn, Jeffrey R.; Penn, Matthew J. Bibcode: 1995itsa.conf.....K Altcode: No abstract at ADS Title: Polarimetric IR Array Observations of a Flare Authors: Penn, M. J.; Kuhn, J. R. Bibcode: 1995itsa.conf..393P Altcode: No abstract at ADS Title: New Observations of IR Coronal Emission Lines Authors: Penn, M. J. Bibcode: 1995itsa.conf...69P Altcode: No abstract at ADS Title: Near-Infrared Emission-Line and Continuum Observations from the 1991 Eclipse Authors: Penn, M. J.; Arnaud, J.; Mickey, D. L.; Labonte, B. J. Bibcode: 1994ApJ...436..368P Altcode: We report observations made during the 1991 July 11 total solar eclipse from the University of Hawaii 61 cm south telescope on the summit of Mauna Kea, Hawaii. The eclipse observations entail CCD imaging of a coronal region on the southeast limb of the Sun using four wavelength channels isolated with narrowband interference filters. We obtain two long exposure images in each channel including the continuum (lambda = 10690 A), the two near-infrared (Fe XIII) emission lines (lambda = 10747, 10798 A), and the He I line (lambda = 10830 A). We calibrate the images to the center-of-disk solar intensity. The (Fe XIII) images are the first coronal images published from these emission lines. We find significant structural differences between the line and continuum images implying large temperature gradients in our small field of view. We compute the line ratio of the two (Fe XIII) emission lines (R) and find that the ratio is within the limits 1.2 greater than or = R greater than or = 15.0. We examine the motion seen in the prominence structure and find transverse velocities of up to about 30 km/s. Finally we see no cold coronal emission to a limit of 2 x 10-7 solar BETA. Title: Ground-based Detection of an Infrared [Si x] Coronal Emission Line and Improved Wavelengths for the Infrared [Fe xiii] Emission Lines Authors: Penn, M. J.; Kuhn, J. R. Bibcode: 1994ApJ...434..807P Altcode: The wavelength of an infrared (Si X) coronal emission line is measured to be 1430.084 +/- 0.006 nm with a coronagraph of the National Solar Observatory at Sacramento Peak (NSOINP). New measurements of the infrared (Fe XIII) emission lines locate the central wavelengths at 1074.617 +/- 0.005 nm and 1079.783 +/- 0.006 nm. The slit-averaged line center intensities were 4.5, 27.8, and 5.2 (in units of 10-6 B(solar)) for the 1430 nm, 1075 nm, and 1080 nm emission lines, repectively. The spatial distribution of (Si X) emission is correlated with the coronal electron density as determined from the (Fe XIII) line ratio. Upper limits are set for coronal emission near 1266 nm and 1523 nm. Title: Coronal electron density measurements using the near-ir [Fe XIII] emission lines Authors: Penn, M. J.; Kuhn, J. R.; Arnaud, J.; Mickey, D. L.; Labonte, B. J. Bibcode: 1994SSRv...70..185P Altcode: Observations made during the 1991 total solar eclipse and recent observations from NSO/Sac Peak are discussed. The ground-based density measurements will be complimentary to SOHO observations, particularly SOHO electron density measurements. Title: Removing Instrumental Polarization from Infrared Solar Polarimetric Observations Authors: Kuhn, J. R.; Balasubramaniam, K. S.; Kopp, G.; Penn, M. J.; Dombard, A. J.; Lin, H. Bibcode: 1994SoPh..153..143K Altcode: Full Stokes polarimetry is obtained using the National Solar Observatory Vacuum Tower Telescope at Sacramento Peak while observing the magnetically sensitive infrared FeI line at wavelength of 1.56μ. A technique is described which makes use of the high magnetic resolution in this spectral range to remove instrumental polarization from observed StokesQ, U, andV line profiles. Title: How bright is the [Si X] 1431 nm coronal emission line? Authors: Penn, M. J.; Kuhn, J. R. Bibcode: 1994SoPh..151...51P Altcode: Airborne eclipse observations of the [SiX] 1430.5 nm coronal emission line are reviewed, and new ground-based out-of-eclipse coronagraph observations obtained at NSO/Sacramento Peak are reported. We find that the [SiX] 1430.5 nm coronal emission line brightness is less than 8 × 10−6B⊙ in small active region corona which showed [FeXIII] 1074.7 nm emission (corrected for sky background) of about 20 × 10−6B⊙. Title: The Source of 5 Minute Period Photospheric Umbral Oscillations Authors: Penn, M. J.; Labonte, B. J. Bibcode: 1993ApJ...415..383P Altcode: We observed the oscillations in the umbrae of two sunspots, using the MCCD imaging spectrograph at the Mees Solar Observatory on Haleakala, Maui. We perform four spatial analyses of the umbral velocity and find that (1) there is more power traveling toward the center of the umbrae than leaving the center of the umbrae (this provides a direct measure of the absorption of p-modes by the sunspot umbrae); (2) the umbral oscillations display power in the same spatial and temporal frequency band as the quiet-sun oscillations; (3) Fourier-Bessel analysis of one umbra shows no obvious resonant frequencies which might represent natural oscillation modes; and (4) the centers of the umbrae have less rms velocity at high spatial wavenumber than the edges of the umbrae. We conclude: (1) the photospheric umbral oscillations are driven by a source external to the sunspot, the global p-mode oscillations; (2) there are no resonant frequencies in the oscillations; and (3) the absorption of acoustic waves occurs inside the umbrae. Title: Coronal Electron Density Measurements from the Total Solar Eclipse of 11 July 1991 Authors: Penn, M. J.; Arnaud, J.; Mickey, D. L.; Labonte, B. J. Bibcode: 1993BAAS...25.1210P Altcode: No abstract at ADS Title: The Source of Five-Minute Period Photospheric Umbral Oscillations Authors: Penn, Matthew J. Bibcode: 1993PASP..105..443P Altcode: Many types of velocity oscillations are observed in the umbrae and penumbrae of sunspots. We describe a project aimed at determining the source of one type of oscillation, the five-minute period photospheric umbra oscillations. The project uses imaging spectroscopy of spot umbrae, measuring the Doppler shift of pure umbral absorption lines to study the temporal and spatial properties of these oscillations. The Mees CCD (MCCD) instrument is an imaging spectroscopy device which uses the 25-cm coronagraph telescope and the 3.0-m coude spectrograph at Mees Solar Observatory (MSO) on Haleakala, Maui. The instrument works with resolving power up to R ~ 200,000 with significant throughput from lambda-3934 A (Ca II K) to lambda ~ 10,000 A. A fast guiding active mirror stabilizes the image during observations. A rapidly writing magnetic tape storage system allows observations to be recorded at 256 kbytes s^-1. We observed the oscillations in the umbrae of two sunspots using the MCCD imaging spectrograph. We observed the Doppler shifts of 18 molecular lines in the umbrae for roughly 50 hours in each spot during the interval of 11 to 16 May 1991. We find no simple correlation between the velocity measured with molecular lines and the velocity measured using two iron lines. We remove solar rotation, image drift, and interpolate all the data onto an even time grid. We perform four spatial analyses of the umbral velocity and find (1) there is more power traveling toward the center of the umbrae than leaving the center of the umbrae (this provides a direct measure of the absorption of p-modes by the sunspot umbrae) (2) the umbral oscillations have spatial and temporal characteristics indistinguishable from the quiet-sun oscillations, (3) a Fourier-Bessel analysis shows no obvious resonant frequencies which might represent natural oscillation modes of the sunspot umbrae, and (4) the centers of the umbrae have less RMS velocity than the edge of the umbrae. >From these analyses we conclude that the photospheric umbral oscillations are driven by an external source and that source is the global p-mode oscillations. (SECTION: Dissertation Abstracts) Title: The Source of Five-Minute Period Photospheric Umbral Oscillations Authors: Penn, Matthew James Bibcode: 1992PhDT.........4P Altcode: 1992PhDT.......172P Many types of velocity oscillations are observed in the umbrae and penumbrae of sunspots. We describe a project aimed at determining the source of one type of oscillation, the five-minute period photospheric umbra oscillations. The project uses imaging spectroscopy of spot umbrae, measuring the Doppler shift of pure umbral absorption lines to study the temporal and spatial properties of these oscillations. The Mees CCD (MCCD) instrument is an imaging spectroscopy device which uses the 25 cm coronagraph telescope and the 3.0 m coude spectrograph at Mees Solar Observatory (MSO) on Haleakala, Maui. The instrument works with resolving power up to R ~ 200,000 with significant throughput from lambda3934 A (Ca II K) to lambda ~ 10000 A. A fast guiding active mirror stabilizes the image during observations. A rapidly writing magnetic tape storage system allows observations to be recorded at 256 kbytes s^{-1}. We observed the oscillations in the umbrae of two sunspots using the MCCD imaging spectrograph. We observed the Doppler shifts of 18 molecular lines in the umbrae for roughly 50 hours in each spot during the interval of 11 to 16 May 1991. We find no simple correlation between the velocity measured with molecular lines and the velocity measured using two iron lines. We remove solar rotation, image drift, and interpolate all the data onto an even time grid. We perform four spatial analyses of the umbral velocity and find (1) there is more power traveling toward the center of the umbrae than leaving the center of the umbrae (this provides a direct measure of the absorption of p-modes by the sunspot umbrae), (2) the umbral oscillations have spatial and temporal characteristics indistinguishable from the quiet-sun oscillations, (3) a Fourier-Bessel analysis shows no obvious resonant frequencies which might represent natural oscillation modes of the sunspot umbrae, and (4) the centers of the umbrae have less RMS velocity than the edge of the umbrae. From these analyses we conclude that the photospheric umbral oscillations are driven by an external source and that source is the global p-mode oscillations. Title: Properties of 5 Minute Period Oscillations in Sunspot Umbrae Authors: Penn, M. J.; Labonte, B. J. Bibcode: 1992AAS...180.0603P Altcode: 1992BAAS...24..736P No abstract at ADS Title: The Mees CCD imaging spectrograph Authors: Penn, Matthew J.; Mickey, Donald L.; Canfield, Richard C.; Labonte, Barry J. Bibcode: 1991SoPh..135..163P Altcode: The Mees CCD (MCCD) instrument is an imaging spectroscopy device which uses the 25 cm coronagraph telescope and the 3.0 m Coudé spectrograph at Mees Solar Observatory (MSO) on Haleakala, Maui. The instrument works with resolving power up to R ≈ 200 000 with significant throughput from λ3934 Å (CaII K) to λ ≈ 10 000 Å. A fast guiding active mirror stabilizes the image during observations. A rapidly writing magnetic tape storage system allows observations to be recorded at 256 kbytes s−1. Currently, the MCCD is used for imaging spectroscopy of solar flares at λ6563 Å (Hα), and velocity measurements of umbral oscillations; future plans include emission line studies of active region coronae, and photospheric studies of solar oscillations. Title: Analysis of p-modes in a Sunspot Umbra Authors: Penn, M.; Labonte, B. Bibcode: 1991BAAS...23.1049P Altcode: No abstract at ADS Title: H alpha Spectra of Dynamic Chromospheric Processes in Five Well-observed X-Ray Flares Authors: Canfield, Richard C.; Penn, Matthew J.; Wulser, Jean-Pierre; Kiplinger, Alan L. Bibcode: 1990ApJ...363..318C Altcode: Simultaneous H-alpha and hard X-ray (HXR) spectra were obtained for five solar flares to determine the relationship of H-alpha profiles and the nonthermal part of the flare represented by the hard X-ray burst. All five flares exhibited impulsive-phase redshifted H-alpha in emission, which was temporarily and spatially associated with intense HXR emission and broad impulsive-phase H-alpha wings. A few small regions within two flares showed a blueshifted H-alpha emission which appeared only early in the impulsive phase and was temporally correlated with the HXR emission but not with broad H-alpha wings. Finally, there were both redshifted and blueshifted absorption spectra with properties fully consistent with those known for erupting and untwisting filaments. Title: Capabilities of the MCCD System at Mees Solar Observatory Authors: Penn, M. J.; Mickey, D. L.; Canfield, R. C. Bibcode: 1990BAAS...22..880P Altcode: No abstract at ADS Title: Hα Flare Observations with the Mees CCD Imaging Spectrograph Authors: Canfield, R. C.; Mickey, D. L.; Penn, M. J.; Wülser, J. -P. Bibcode: 1990BAAS...22..809C Altcode: No abstract at ADS Title: Moat Flows Using Magnetic Tracers Authors: Penn, M. J.; Labonte, B. J. Bibcode: 1988BAAS...20..680P Altcode: No abstract at ADS Title: The excitation and damping of solar oscillations Authors: Libbrecht, K. G.; Popp, B. D.; Kaufman, J. M.; Penn, M. J. Bibcode: 1986Natur.323..235L Altcode: Present theories suggest two classes of excitation processes which may be responsible for the observed amplitudes of solar p-mode oscillations-self-excitation of the modes via an overstability mechanism such as the K mechanism 2, and stochastic excitation by turbulent convection2-4. We now have data which stand in support of the latter mechanism. Linear overstability calculations are still ambiguous, because of the uncertainties involved in including turbulent viscous damping of the modes. Nevertheless no calculation predicts overstable f-modes, and these modes are observed on the Sun. Furthermore no nonlinear damping mechanism has yet been proposed which would limit the growth of overstable modes to their observed amplitudes. Assuming the modes are stably damped, the theory of mode excitation by convective turbulence now gives mode amplitudes that are in agreement with observations4. In this letter we use data from Big Bear Solar Observatory to compare theory and observation in detail. In particular, our data show that the energy per oscillation mode is nearly constant at low mode frequencies, and is approximately independent of degree at low degrees. The total energy in all the oscillation modes is estimated at ~1034erg.