Williams College Scientists Travel to View Solar Eclipse


A Williams College team of faculty and students is preparing to make scientific observations of the total solar eclipse of the Sun that will sweep across the far side of the Earth on July 22.  Jay Pasachoff and Bryce Babcock of Williams College's astronomy and physics departments are joined by five undergraduates for their astronomical pursuits.  The pair has been working together on a series of expeditions, most recently to study Pluto and its moon Charon and to last summer's total solar eclipse in Siberia.


The expedition is on a low mountaintop near Hangzhou, China.  The Williams College group will be on site a week in advance, to give them time to set up, test, and align their more than nearly a ton of equipment.  They are working with Prof. Yihua Yan of the Beijing Astronomical Observatory and Ms. Lin Lan of Hangzhou High School.


The Williams team will have almost six minutes to make their observations of the sun's corona, the faint outer halo of million-degree gas that is hidden by the everyday blue sky at times other than those of total solar eclipses.  That time is relatively long compared with the length of the previous eclipses; this summer's eclipse is the longest of the 18 year 11 1/3 day eclipse cycle.


Two of their experiments involve searching for the mechanism by which the solar corona is heated to millions of degrees by taking rapid series of images with new electronic cameras through special filters.  One of the filters passes a narrowly defined color in the green and the passes a wider band of green, the narrow band emitted by gas in the corona from iron that has been heated to such high temperatures that it has been stripped of 13 of its normal quota of 26 electrons and the wider band as a control.


A third experiment involves matching images to those that had been taken by a telescope now defunct in space on board the Solar and Heliospheric Observatory (SOHO), a satellite built and operated by the European Space Agency and NASA.  Both of those organizations have arranged with Pasachoff to receive a digital image immediately after the eclipse, if the eclipse weather is clear, to merge with their own spacecraft images and to distribute to the public.  


The Williams expedition will further obtain a wide variety of digital and film eclipse images.  Pasachoff works with Dr. Vojtech Rusin of the Slovakian Academy of Sciences and Dr. Miloslav Druckmüller of the Brno Technical University, Czech Republic, on high-resolution computer image processing and its analysis.


Student members of the expedition will include Katherine DuPré '10, Yung Hsien Ng (Caroline) Tam '11, Sara Dwyer '11, Huajie (Charles) Cao '09, and exchange student Rachel Wagner-Kaiser '11 (from Vassar College, as a Keck Northeast Astronomy Consortium Summer Fellow).


As Chair of the International Astronomical Union's Working Group on Eclipses, Pasachoff maintains a Website at http://www.eclipses.info that links to various eclipse-related resources.  


The Expedition is funded in part by a grant from the Committee for Research and Exploration of the National Geographic Society, with additional funding from Williams College, including its Brandi Fund and its Rob Spring Fund.