Presentation #229.02 in the session “Solar Physics Division (SPD): Eclipses and Solar Wind”.
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.