WILLIAMSTOWN, Mass. — Jay Pasachoff, director of Williams College's Hopkins Observatory and Field Memorial Professor of Astronomy, announced the Williams College Eclipse Expedition's plans for the Dec. 4 total solar eclipse over and near Antarctica.

 

Pasachoff has been observing total solar eclipses together with Williams College students for 50 years, since he came to Williams in 1972 and took students to an eclipse only 10 days after his arrival.

 

Major research about the outer layer of the Sun, the solar corona, requires the Sun visible in the sky without the blue sky blocking the view, which is accomplished by the passage of the Moon before the everyday Sun. Such an event usually occurs about every 18 months.

 

Eight students plus alumni joined Pasachoff in Oregon for the 2017 totality, and three students and an alumnus joined him in 2019 in Chile. Similar work in Chile for the 2020 totality was blocked by Covid travel restrictions. Eclipse viewing resumed with an annular (ring-shaped-everyday-sun) eclipse with residual sunlight surrounding the Moon in an eclipse flight over southern Canada out of Minneapolis on June 10, 2021.

 

For the Dec. 4 totality, the Williams group will leave New York's John F. Kennedy International Airport for Santiago, Chile, on Sunday, Nov. 28. It includes Pasachoff and Dr. Naomi Pasachoff (research associate in the astronomy department), Peter Knowlton '21.5, Anna Tosolini '23, Muzhou Lu '13 (now a SpaceX Flight Engineer), Dr. David Sliski (research associate in the astronomy department and also of the University of Pennsylvania), and instrument-maker Aristeidis Voulgaris (optomechanics, Thessaloniki, Greece). 

 

On Friday evening, Dec. 3, the team will join about 30 other professional and amateur astronomers on a charter flight on a LATAM airlines 321 aircraft to fly 2,000 miles south to Punta Arenas, near the southern point of Chile. A few hours later, early the morning of the Saturday, Dec. 4, the flight plan will take the group almost due east, and they will view the eclipse out the windows on one side of the plane for 1 minute 45 seconds of totality from an altitude of 39,000 feet. The corona should be visible almost straight out of the plane's windows at an angle of 4° above the horizon.

 

The expedition was planned by Pasachoff's collaborator Dr. Glenn Schneider of the Steward Observatory, University of Arizona. Pasachoff and Schneider collaborated on observations on a similar flight to view totality from over Antarctica, though out of Australia, for the 2003 total solar eclipse.

 

The hope is to compare the shape of the coronal streamers with predictions made this week by Predictive Science Inc., San Diego, based on magnetic-field measurements of the solar surface made by NASA's orbiting Solar Dynamics Observatory. The hope continues that within 24 hours or so, colleagues can make computer composites from multiple images to show the shape of the coronal streamers as they fade with distance from the Sun, and again--as was done for the 2020 eclipse viewed from Chile and Argentina--posted by NASA's Goddard Space Flight Center. In 2020, an eclipse comet appeared, and was the subject of another press release; whether there will be new comets or Coronal Mass Ejections during the 2021 eclipse is not yet, of course, known.

 

Another major research topic of Pasachoff's group is how the solar corona is heated to millions of degrees, even though the everyday surface of the Sun is only about 12,000° Fahrenheit.  Somehow, energy is being injected--no doubt with the help of the Sun's magnetic field--into the corona. Voulgaris's spectrographs break down the coronal light into components that reveal the high temperature. 

 

The research is relevant to Pasachoff's Astronomy 412 tutorial on Heliophysics this semester for 9 astrophysics majors.

 

This eclipse will be at least Jay Pasachoff's 74th solar eclipse, of which 36 will have been total, and Naomi Pasachoff's 47th solar eclipse, including 22 totals.

 

A coordinated part of our expedition will observe the total eclipse in Antarctica. It includes Christian Lockwood '20, Theo Boris, a Collegiate School student who audited Pasachoff's Zoom astronomy course last year, as well as citizen scientists Janet Boris and Peter Boris of New York City, who will also be working with the equipment. They will land on the ice at Union Glacier with more than 850 pounds of telescopic equipment. Their scientific cameras are designed for an experiment to measure sub-second oscillations in magnetic loops at the Sun's edge, as a signature of "surface Alfvén waves" as a mechanism of coronal heating to its incredibly high temperature.  They will also image the coronal streamers and will provide a livestream for NASA.

 

A further coordinated part of our expedition is the collaboration with professor Patricio Rojo of the astronomy department of the University of Chile. He visited Williamstown last month to pick up additional equipment to that Pasachoff provided him for last year's eclipse. Rojo has previously collaborated with Pasachoff on stellar occultations. He is part of the official Chilean research team that will be brought by the Chilean Air Force to land on Union Glacier, and already on Nov. 20 he was in place in Punta Arenas awaiting flying weather for the team to Antarctica. He is carrying Celestron and Nikon telephotos and Nikon cameras from Williams College, with filters by Questar and Thousand Oaks Optical, and had a spectrograph from Voulgaris specially made.

 

Looking forward, Pasachoff is on the American Astronomical Society's Eclipse Task Force's Formal Education working group, in preparation for the annular 2023 and total 2024 solar eclipses with paths that cross Mexico and the United States. This working group aims to promote and coordinate networks and resources for meaningful student eclipse experiences and for building capacity in formal education (K-12 and Higher Ed) to address solar science and the eclipse.

 

 JMP's current research about eclipses is sponsored by grant AGS-1903500 of the Solar Terrestrial Program, Atmospheric and Geospace Sciences Division of the NSF, succeeding AGS-1602461 from the period of the 2017 eclipse.