Abstracts for the American Astronomical Society’s Solar Physics Division meeting, June 7-9, 2021 (virtual)

Observational Validation Of Predictions For The 2020 Eclipse Corona 
J. M. Pasachoff1, C. Downs2, J. Linker2, R. Caplan2, P. Riley2, R. Lionello2, A. Möller3, V. Rusin4, R. Vanur4, W. Carlos5
1Hopkins Observatory, Williams College, Williamstown, MA, 2Predictive Science, San Diego, CA, 3Arbeitskreis Meteore e.V. (AKM), Berlin, GERMANY, 4Astronomical Institute, Tatranská Lomnicá, SLOVAKIA, 5-, New York, NY. 

Using observations from Argentina during the eclipse of 14 December 2020, compare our observations to a prediction simulation of the eclipse corona, developed by Predictive Science Inc. This 2020 prediction was based on a thermodynamic magnetohydrodynamic (MHD) model of the corona with a new two-temperature formulation and updates to a wave-turbulence-driven (WTD) heating and acceleration model. A comparison of the observed and predicted white light morphology is used to assess and inform the WTD model parametrization. Using observations by AM from Piedra del Águila, Argentina, we provided a quick composite by Williams College for comparison with the Predictive Science prediction for a NASA press release the following day (https://www.nasa.gov/feature/goddard/2020/scientists-use-nasa-data-predict-appearance-corona-dec-14-total-solar-eclipse) and a later composite by RV for a NASA press release about a newly discovered sungrazer comet that soon followed (https://www.nasa.gov/feature/goddard/2020/recently-discovered-comet-seen-during-2020-total-solar-eclipse-SOHO). See also Pasachoff, Jay M., 2021, Preliminary Report on the 14 December 2020 Total Solar Eclipse Observations, for International Astronomical Union Symposium 367: Education and Heritage in the Era of Big Data in Astronomy, submitted (Cambridge University Press, 2021); Pasachoff, Jay M., 2021, The 2020 Total Eclipse, Astronomy Magazine, April, pp. 47-51. Acknowledgments: JMP’s research for this eclipse was sponsored by grant AGS-1903500 of the Solar Terrestrial Program, Atmospheric and Geospace Sciences Division of the NSF. PSI was supported by AFOSR, NASA, and NSF. VR and RV have been supported by the project VEGA ~ 2/0048/20 (Slovak Academy of Sciences). We thank Lina Tran and Joy Ng of NASA’s Goddard Space Flight Center for their work on the prediction/verification and eclipse-comet press releases. 

High-frequency Forbidden-line Coronal Oscillations As A Test Of Coronal Heating Methods

J. M. Pasachoff1, M. J. Person2, A. Wang1
1Hopkins Observatory, Williams College, Williamstown, MA, 2Wallace Observatory, MIT, Cambridge, MA.

We report on data reduction carried out in 2020 on high-frequency (2 Hz) observations in the coronal green line (Fe XIV, 637.4 nm) and the coronal red line (Fe X, 530.3 nm) at the Williams College solar eclipse expedition to Salem, Oregon, for the August 21, 2017, totality. The observations and analysis followed previous work, testing the predictions of coronal heating from surface Alfvén waves, which would be at much higher frequency than the body waves in coronal loops usually invoked and studied. AW, in his A.B. senior thesis with joint advisors in the Astronomy and Mathematics departments, computed power spectra. He found some excess power at the high frequencies but only in the pixels closest to the solar limb, raising questions of equipment vibrations, raising questions for further observations. Newly designed equipment, with new detectors, was built for the 14 December 2020 total solar eclipse, but COVID-19-related travel bans at Williams College and at MIT prevented us from taking the apparatus. We look forward to using it at the total solar eclipses of 2023 in Australia and 2024 in Mexico/US.
Acknowledgments: Our research has been supported in large part from grant AGS-1903500 from the Solar Terrestrial Program of the Atmospheric and Geospace Sciences Division of the National Science Foundation and prior NSF grants, and from the Committee for Research and Exploration of the National Geographic Society, with additional support from Sigma Xi. Additional support for undergraduate participation came from the NSF, the NASA Massachusetts Space Grant Consortium, and the Clare Booth Luce Foundation, with travel support from the Freeman Foote Fund, the Rob Spring Fund, the Brandi Fund, and other sources at Williams College.


The International Astronomical Union’s Working Group On Solar Eclipses

J. M. Pasachoff
Hopkins Observatory, Williams College, Williamstown, MA.

The International Astronomical Union’s Working Group on Solar Eclipses of Divisions C (Education, Outreach, and Heritage) and E (Sun and Heliosphere) has the following tasks: (a) Working with the general public, providing materials and links to explain why eclipses are interesting to watch, how to observe them safely, and what science is being studied; and (b) Working with professional astronomers from around the world, to help coordinate their expeditions to total solar eclipses, including helping them work with customs in various countries about the temporary importation of scientific equipment. With our especially easy-to-remember website URL of http://eclipses.info, we endeavor to be a one-stop location for a wide variety of observing aids for professional and amateur astronomers. We link, for example, to the major sites for eclipse mapping. For professionals, we hope to be able to advise on the temporary duty-free import of equipment for eclipse observations. We provide links to books and summary articles about solar eclipses, and information about safe observing of solar eclipses (while trying to explain their excitement and value to the general public). • Members: Jay Pasachoff (USA, Chair), Iraida Kim (Russia), Jagdev Singh (India), Vojtech Rusin (Slovakia, through 2021), Yoichiro Hanaoka (Japan), Zhongquan Qu (China), Beatriz Garcia (Argentina), Patricio Rojo (Chile), Xavier Jubier (France), Fred Espenak (US), Jay Anderson (Canada), Glenn Schneider (US), Michael Gill (UK), Michael Zeiler (USA), Bill Kramer (USA); associates: Michael Kentrianakis (USA), and Ralph Chou (Canada). • For the 2019 and 2020 total eclipses in Chile and Argentina, Patricio Rojo (U. Chile) and Beatriz Garcia (Pierre Auger Observatory, Argentina) were added to the Working Group.• For the next triennium, September 2021-September 2024, given visibility of totality from Learmonth, Western Australia in 2023, we propose adding Terry Cuttle (public outreach, Australia) and Michael Wheatland (U. Sydney; an editor of the journal Solar Physics). We also propose adding Andreas Möller (Germany; who will collaborate with Bill Kramer on an archive of eclipse publications and maintain the eclipse-chaser.com website). Prof. Wheatland is an IAU member; Mr. Cuttle and Mr. Möller would be associates. Also we add Costantino Sigismondi (Italy) and Kevin Reardon (US National Solar Observatory, USA). For the three eclipses in Spain (two total and one annular) in 2025-2026-2017, we add Mohamad Soltanolkotabi. We also look ahead to eclipses in Australia in 2028 and 2030. The 2027 eclipse continues from Spain across North Africa. The 2030 eclipse that reaches Australia starts over South Africa. • JMP represents this IAU Working Group on the American Astronomical Society’s Solar Eclipse Task Force for the 2023 and 2024 eclipses (see http://eclipse.aas.org): Solar Eclipse Across America. Each year, we provide “Eclipses” for the International Geophysical Calendar (International Space Environmental Service), http://www.spaceweather.org/ISES/info/geocal/geocal.html• Acknowledgment: JMP’s current solar eclipse activity is sponsored in large part by grant 1903500 of the Solar Terrestrial Program, Atmospheric and Geospace Sciences Division, NSF.