Media contact: Jay M. Pasachoff, [email protected]; cell phone: 617-285-6351
WILLIAMSTOWN, Mass., May 8, 2012 – An annular solar eclipse will sweep across Asia, the Pacific Ocean, and the western United States on May 20. Williams College astronomy professor Jay Pasachoff will observe it from New Mexico, joined by professional colleagues and by eight undergraduate students. At an annular eclipse, a ring of everyday sunlight remains around the silhouette of the Moon, even at the eclipse’s peak. Coordinated observations will be made with colleagues in charge of radio telescopes in California and of telescopes on spacecraft.
Pasachoff, Chair of the International Astronomical Union’s Working Group on Solar Eclipses, will be observing his 55th eclipse of the Sun. “Though the sky won’t get as dark as it does during a total solar eclipse, the Moon will cover just about the whole Sun at one time or another, so I arranged to observe it with the world’s largest and best array of radio telescopes,” said Pasachoff. “Since we know the rate at which the Moon appears to move across the Sun, by taking data every second, we can get high resolution showing exactly where the Sun’s radio emission comes from, getting higher accuracy in viewing sunspot regions than is otherwise possible. We can compare these positions with those that shine in x-rays or the extreme ultraviolet radiation being observed from satellites. The results should help us understand how flares and other solar activity arise,” said Pasachoff. “The currently approaching maximum of the sunspot cycle should provide us with several active regions on the solar disk that we can study.”
The scientific studies are sponsored by a grant to Williams College, with Pasachoff as Principal Investigator, from the National Science Foundation’s Solar Research Program of the Atmospheric and Geospace Sciences Division. The grant covers both the annular eclipse of May 20 and a total solar eclipse Pasachoff and his colleagues and students will observe from Australia on November 14.
For the annular eclipse, Pasachoff has recruited colleagues across the country to use the major solar facilities that are in or close to the band of annularity, which is a couple of hundred miles wide and thousands of miles long. He will be observing at the Jansky Very Large Array of the National Radio Astronomy Observatory, whose linked 27 antennas are located 60 miles west of Socorro, New Mexico. Pasachoff will be joined there by eight of his students and by Dr. Bryce Babcock, also of Williams College’s Astronomy Department. Pasachoff is working there with Dr. Dale Gary and Samuel Tun of the New Jersey Institute of Technology, Dr. Timothy Bastian and Bryan Butler of the National Radio Astronomy Observatory, and Bin Chen of the University of Virginia, all experienced in using the JVLA for solar research.
The six Williams students involved are taking a course in solar physics from Pasachoff this semester; most are supported in part by a grant from the Massachusetts Space Grant Consortium, a NASA-funded project. The Williams students are Allen Davis ’14 from North Stonington, Conn., Markus Gonzales ’13 from Lake Odessa, Mich., Muzhou Lu ’13 from Queens, N.Y., Shubhanga Pandey ’13 from Kathmandu, Nepal, Ben Oliva ’12 from Pacific Palisades, Calif., and Ben Seiler ’12 from New York, N.Y. Auditor Ryan Barley of the Massachusetts College of Liberal Arts, North Adams, will join them. Barley is from Westfield, Mass. Also participating will be Eric Edelman of Wesleyan University, a Keck Northeast Astronomy Consortium Summer Fellow from Pleasanton, Calif., working with Pasachoff through an NSF grant in the Research Experiences for Undergraduates program.
Coordinated measurements of the effects of the eclipse on the Earth’s atmosphere, through a perhaps 10°F drop in temperature and otherwise, will be carried out nearby by Michael Thomas Roman of Cornell University in coordination with Professor Marcos Peñaloza-Murillo from the Universidad de los Andes in Merida, Venezuela, who is spending a Fulbright leave with Pasachoff at Williams, and by Naomi Pasachoff, whose measurements at the 2010 total solar eclipse in Easter Island are also being studied.
Robert Lucas of Sydney, Australia, Michael Kentrianakis of New York, Michael Doochin and Linda Kartoz of Nashville, Tenn., and Phyllis Babcock are among the experienced eclipse observers who will join the group at the JVLA site.
Further, Pasachoff, Gary, Bastian, and Chun are working with Stephen White of Kirtland Air Force Base in observations made with an array of radio telescopes known as CARMA (The Combined Array for Research in Millimeter-wave Astronomy), which is located in the Inyo Mountains above the Owens Valley near Big Pine, California. CARMA will observe at shorter radio wavelengths than the JVLA, allowing views of a different level of the Sun’s atmosphere.
In addition, Pasachoff has recruited Dr. Thomas Kuiper of Caltech’s Jet Propulsion Laboratory, a NASA-funded facility, to use their 34-m (100-foot) radio antenna near Goldstone, Calif., to observe the Moon cover and uncover the Sun, allowing observations at still different frequencies. Pasachoff and Kuiper had worked together 40 years ago on radio observations of the Sun.
Space observations will be made with the same facilities as will be used for coordinated observations of the June 5 transit of Venus, about two weeks after the eclipse in an unusually astronomically busy spring. They include NASA’s Solar Dynamics Observatory and two U.S. telescopes, Solar Optical Telescope (SOT) and X-ray Telescope (XRT) on the Japanese Hinode spacecraft, as well as measurements of dimming solar flux from NASA’s ACRIMsat, with its Active Cavity Radio Irradiance Measurement 3 device run by Richard Willson out of JPL and NASA’s SORCE, with its Total Irradiance Measurement experiment run by Greg Kopp of the University of Colorado.
Pasachoff will also be coordinating observations of the Baily’s beads that mark the beginning and the end of totality with William Ryan and Eileen Ryan of the Magdalena Ridge Observatory of the New Mexico Institute of Mining and Technology (New Mexico Tech) in Socorro. A NASA-funded Williams College POETS (Portable Occultation, Eclipse, and Transit System) camera is on long-term loan there, largely for the studies of the sizes and atmospheres of Pluto and other objects in the outer solar system, the subject of recently regranted support to Pasachoff from NASA’s Planetary Astronomy Program. It will be used on the 12-inch telescope that guides the observatory’s 95-inch telescope to monitor the Baily’s beads, bits of sunlight that shine through valleys on the lunar edge just as the Moon begins or ends its central passage over the solar disk. Francis Baily, in his 1836 paper reporting on the phenomena now named after him that he observed at the annular eclipse of that year, describes some aspects that may be similar to the black-drop effect that Pasachoff and colleagues will study at the June 5 transit of Venus. The Pasachoff faculty, staff, and student team will visit the Magdalena Ridge Observatory on eclipse day, before they watch the eclipse from the Jansky Very Large Array’s telescopes. The event will be Pasachoff’s 14th annular eclipse.
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