Press Release

Williams College Team to Observe Outback Eclipse

Prof. Jay Pasachoff, Director of Williams College's Hopkins Observatory, is heading a team of 22 scientists and students to observe the total solar eclipse of Wednesday, December 4. They are in Ceduna, Australia, at the south edge of the Outback, and have been setting up about 1500 pounds of telescopes, computers, electronic cameras, and other equipment for over a week.

The total solar eclipse of December 4, will cross southern Africa (parts of Angola, Botswana, Zimbabwe, South Africa near Kruger Park, and Madagascar) during the early morning during the rainy season, and will then head out over the ocean. It will reach land near sunset in Ceduna, Australia, on the Great Australian Bight on the coast of South Australia and about 780 km west of Adelaide. The eclipse will end inland, past Woomera, not many minutes later.

Williams College's expedition will make scientific observations of the solar corona during the eclipse. Eleven Williams College undergraduate students are participating in addition to Williams College faculty Prof. Jay M. Pasachoff, Dr. Bryce Babcock, and Dr. Steven Souza. Additional staff includes Lee Hawkins from Appalachian State University, Dr. Raymond Smartt from the U.S. National Solar Observatory, and Robert Lucas from the University of Sydney. Alumus Rob Wittenmyer '98, a graduate student in astronomy at San Diego State University, and former Williams colleague Stephan Martin will also participate.

Williams students on the expedition, who are mixing in quantum-mechanics homework with their eclipse preparations, are David Ticehurst '03, Kristen Shapiro '03, Lissa C. F. Ong '04, Davis V. Stevenson '04, Sarah H. Croft '04, Jesse W. Dill '04, Paul M. Crittenden '04, Galen M. Thorp '04, John A. BackusMayes '05, Kamen A. Kozarev '05, and Terry-Ann K Suer '05.

The group's work is described at http://www.williams.edu/astronomy/eclipse, and a current site showing images from Ceduna is at http://users.bigpond.com/williamseclipse. The eclipse itself will be broadcast live at http://www.csiro.au/helix/eclipse. The Web site for the Outback Eclipse in Ceduna is http://www.eclipse2002.com.au. General maps and other information about this and other eclipses is at a site run by Williams College for the International Astronomical Union at http://www.eclipses.info.

The expedition is to carry out three major experiments. First, they will be observing loops in the solar corona through a special filter at high cadence to further their observations of oscillations that are thought to be a source of coronal heating. The observations are part of the investigation of how the solar corona that will become visible at the eclipse is heated to a temperature of 2 million degrees Celsius. Second, they will be mapping the polarization of the corona, which reveals how much of the coronal light comes from the corona itself instead of being added on in interplanetary space. Third, they will be filling in the gap in coverage of the Solar and Heliospheric Observatory, SOHO, a space satellite of NASA and the European Space Agency. NASA's Goddard Space Flight Center is poised to receive the Williams Expedition's image immediately after the eclipse to mosaic it with jointly planned observations from two of their space telescopes on board the satellite. The Williams group is also working in liaison with scientists at the Harvard-Smithsonian Center for Astrophysics, including Daniel B. Seaton '01, to observe the same region of the Sun with NASA's Transition Region and Coronal Explorer satetllite, TRACE, as with one of the Williams instruments.

Pasachoff, chair of the Working Group on Eclipses of the International Astronomical Union (IAU), will be observing his 35th eclipse.

For more information, contact:

Prof. Jay M. Pasachoff on site in Ceduna on his Australian cell phone at

011 61 4 09 220 873 or by e-mail at jay.m.pasachoff@williams.edu.

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Pasachoff also chairs the Subcommittee on Public Education at the Time of Eclipses of the IAU's Commission on Astronomy Education and Development. He wrote the "Peterson Field Guide to the Stars and Planets" in addition to astronomy texts. He is co-author, with Leon Golub, of the trade book "Nearest Star: The Surprising Science of Our Sun," published in 2001 by Harvard University Press. See www.eclipses.info for IAU related Web pages, and www.solarcorona.com for book Web pages.

During the 1998 total eclipse in Aruba, the 1999 total eclipse in Romania, and the 2001 total eclipse in Zambia, the Williams expeditions conducted several experiments and took many additional photographs and electronic images and videos. One of the experiments mapped the temperature of a quadrant of the sun's corona, the outermost layer of its atmosphere, which can attain four million degrees Fahrenheit (about two million Celsius) though its surface is only 11,000 degrees Fahrenheit (about 6,000 Celsius).

A second experiment was conducted in collaboration with scientists at the Harvard-Smithsonian Center for Astrophysics, NASA's Goddard Space Flight Center, and the U.S. Naval Research Laboratory. The Williams group took images of the solar corona during the eclipse for comparison with images captured by a rocket launched by Leon Golub of the CfA and with spacecraft images from the Extreme-ultraviolet Imaging Telescope and the Large Angle Spectroscopic Coronagraph (LASCO) aboard the Solar and Heliospheric Observatory (SOHO) in space. Daniel B. Seaton, a Williams student now at the CfA, continues to work on the reduction of these data.

In a third experiment, the Williams scientists measured the polarization of the outer corona for comparison with measurements from the LASCO and Ultraviolet Coronagraphic Spectrometer aboard SOHO. The UVCS observations are in collaboration with scientists from the Harvard-Smithsonian Center for Astrophysics.

A fourth experiment, to look for waves in loops of gas at the edge of the sun, worked well in Aruba and Romania but failed in Zambia when a computer controlling its electronic detector stopped accepting commands. The waves would be a sign of a method of coronal heating. The Williams team is especially looking forward to new data from this experiment in Australia.

A series of Williams College thesis students have worked on the eclipse results, including Timothy McConnochie '98 (now a graduate student in astronomy at Cornell), Kevin Russell '00 (Fulbright scholar in astronomy/physics and now a graduate student in international affairs at Johns Hopkins), Daniel Seaton '01 (now a research assistant at the Harvard-Smithsonian Center for Astrophysics), Gabriel Brammer '02 (now a data analyst at the Space Telescope Science Institute), and David Ticehurst '03 (who is still at Williams and who is hoping for new data).

Many of the images from past eclipses have been assembled into mosaics by Wendy Carlos. See, for example, www.williams.edu/astronomy/eclipse.

The expeditions have been supported by the National Science Foundation, the National Geographic Society, the Keck Northeast Astronomy Consortium, the Massachusetts Space Grant Consortium, the Science Laboratories at Williams College, and the Safford Fund, Brandi Fund, and Rob Spring Fund at Williams.

The group spends months planning and over a week setting up and testing equipment on site, all in preparation for the totality. The corona is visible from earth only while the sun is totally eclipsed. For the December 4 eclipse, totality will last only about 33 seconds from Ceduna and the sun will be only 9 degrees above the horizon, though looking over a water. Weather statistics based on past years indicate that there is about a 2/3 chance of seeing totality.

Williams has a rich history of scientific expeditions, including the first ever sent by an American college, in 1835 to Nova Scotia.

Images from past solar eclipse expeditions expeditions are available at www.williams.edu/astronomy/eclipse.

Some of the eclipse equipment has recently been used to observe occultations of stars by Pluto. For a summary of these very successful observations, notably the event of 20 August 2002, see:
www.williams.edu/astronomy/mkpluto.html
www.lowell.edu/Press/20020815.html.

References:

Jay M. Pasachoff, Peterson Field Guide to the Stars and Planets (Houghton Mifflin, 2000)

www.williams.edu/astronomy/fieldguide

Leon Golub and Jay M. Pasachoff, Nearest Star: The Surprising Science of Our Sun (Harvard University Press, 2001).

www.williams.edu/astronomy/neareststar

Jay M. Pasachoff, Astronomy: From the Earth to the Universe, 6^th ed. (Brooks/Cole, 2002)

www.williams.edu/astronomy/jay