Astronomer Jay Pasachoff Receives NSF Grant to Support Solar-Eclipse Research

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WILLIAMSTOWN, Mass., May 24, 2019—Jay Pasachoff, Field Memorial Professor of Astronomy and director of Williams College’s Hopkins Observatory, has received a grant from the U.S. National Science Foundation (NSF) for support of his solar-eclipse research over the next three years.

The grant includes support for expeditions for his team of students and colleagues for the July 2, 2019, total eclipse in Chile; for the December 14, 2020, total eclipse in Argentina, and the December 4, 2021, total eclipse on and over Antarctica. The 2019 total eclipse will be Pasachoff’s 35th, and his 71st solar eclipse overall. Pasachoff is currently on sabbatical leave at the Carnegie Observatories, based at their headquarters in Pasadena, California.

Supporting the research is the Solar Terrestrial Program of the Atmospheric and Geospace Sciences Division of the NSF. The grant, for $251,000 over the three years, includes travel, equipment, summer salary for faculty and students, shipping charges, scientific-meeting participation, and publication charges. The grant is a successor to two immediately previous eclipse-related grants from that program.

At the July 2 eclipse this year, the research will include studies of the solar corona. Undergraduates Christian Lockwood ’20 (Quogue, Long Island, N.Y.), John Inoue ’20 (Mt. Angel, Ore.), and Erin Meadors ’20 (Albuquerque, N.M.) will participate. Additional support is being received from the NASA Massachusetts Space Grant Consortium for Lockwood and Inoue and for all three students’ expeditionary support with a Global Initiative Award from Williams College. Lockwood and Meadors had been part of Williams College’s NSF and National Geographic Society funded expedition to Oregon for the 2017 eclipse, which Inoue had also observed in Oregon, from his family home. Eight Williams College undergraduates had participated in that expedition.

The research will also include studies of the effect of the eclipse darkening on the Earth’s atmosphere, carried out in collaboration with visiting Venezuelan research scientist Marcos Peñaloza-Murillo, a former Fulbright fellow at Williams. He worked with Pasachoff in supervising the senior thesis this year of Ross Yu ’19 on that subject from the observations of temperature, pressure, and wind at the 2017 eclipse at the Williams College site and at other sites around the U.S.

The solar corona is different at each eclipse, sometimes with particular solar mass ejections and in any case varying with the 11-year sunspot cycle. The 2019 eclipse corresponds to a deep minimum of the sunspot cycle, with most days having the sun entirely free of sunspots, allowing the astronomers to view magnetic plumes of gas rising above the poles of the sun, much as lines of force can be visualized stemming from the ends of bar magnets. One project is in collaboration with a team of scientists from Predictive Science Inc in California, already the source of a joint paper about the 2017 results that appeared in the journal Nature Astronomy, in which a composite image made from Williams College observations by New York musician Wendy Carlos, in collaboration with Pasachoff, was used to compare with the predictions released before the eclipse based on a month’s observations of the solar magnetic field.

In addition to his eclipse site on the centerline of the eclipses’s totality north of La Serena, Chile, at an altitude of 2500 feet above sea level, Pasachoff has won one of five coveted slots for a team of four at the Cerro Tololo Inter-American Observatory at their 7500-foot altitude. The arrangements were made by the Associated Universities for Research in Astronomy (AURA), which is also assisting with the logistics. Among the observations his team will make there will be some that result from a collaboration with Aris Voulgaris, a Greek instrumentation builder, who is providing three spectrographs to view images of the solar corona’s million-degree gas at different visible-light wavelengths that correspond to different temperature regimes.

Voulgaris is also modifying a special type of high-resolution filter, known as a Lyot filter, borrowed by Pasachoff from the New Jersey Institute of Technology’s Big Bear Solar Observatory in California, in order to show nine-times-ionized argon in the solar corona at such spectral purity for the first time. Working with Voulgaris will be Kevin Reardon, a Williams College alumnus who graduated in 1992 and who is now on the staff of the National Solar Observatory in Boulder, Colo. At the Cerro Tololo site, additional high-resolution optical observations will be gathered by David Sliski from the University of Pennsylvania and by his father, optical-instrumentation specialist Alan Sliski, from Lincoln, Mass.

Pasachoff has also supplied a lens as part of a collaboration with Glenn Schneider of the University of Arizona’s Steward Observatory to be flown by the latter on a chartered Boeing 787 out of Easter Island, to get over eight minutes of totality, longer than ever possible from land. The differences between the coronal structure from the Pacific site compared with the Chilean site will be used to again measure the speed of motions in the corona and the underlying changes in the coronal magnetic field. Further, as part of the international collaboration, Schneider will also be using on board a spectrograph provided by Voulgaris.

Pasachoff and his team are also collaborating with Zoran Mikic, Jon Linker, and Cooper Downs of Predictive Science Inc of San Diego, California. As they did for a joint article that appeared in the journal Nature Astronomy with results from the 2017 total eclipse, a few days before the eclipse the Predictive Science Team calculated what the detailed shape of the coronal streamers should be like based on a month of prior observations from a NASA spacecraft of the Sun’s magnetic field, including any sunspots. The article validated the prediction in part with a composite eclipse image processed and interactively optimized by Wendy Carlos of New York City from images made in Oregon by Pasachoff’s team.

The data from the Chile eclipse observations will be brought back to Williamstown to be studied by Pasachoff, Lockwood, and Inoue over the summer and as senior theses over the next academic year, with further studies taking even longer.

The group at the centerline will also include scientists from the Yunnan Observatory in China, linked through Pasachoff’s role as chair of the Working Group on Solar Eclipses of the International Astronomical Union, and also arranged with travel agent Mark Sood of A Classic Tours Collection of Redondo Beach, Calif. Pasachoff and Sood have carried out over 15 eclipse expeditions together; a tour group of over 100 people will join them in Chile. Teacher William Fenton and seven students from the Hotchkiss School are included. The tour group in Oregon included alumni both of Williams College and of Pasachoff’s Harvard alumni class.


Founded in 1793, Williams College is the second-oldest institution of higher learning in Massachusetts. The college’s 2,000 students are taught by a faculty noted for the quality of their teaching and research, and the achievement of academic goals includes active participation of students with faculty in their research. Students’ educational experience is enriched by the residential campus environment in Williamstown, Mass., which provides a host of opportunities for interaction with one another and with faculty beyond the classroom. Admission decisions on U.S. applicants are made regardless of a student’s financial ability, and the college provides grants and other assistance to meet the demonstrated needs of all who are admitted.


Published May 24, 2019