ASTRONOMY DEPARTMENT

Faculty of the Astronomy Department included Karen B. Kwitter, Ebenezer Fitch Professor of Astronomy and Chair; Jay M. Pasachoff, Field Memorial Professor of Astronomy; and Steven P. Souza, Lecturer in Astronomy and Observatory Supervisor. Bryce A. Babcock, Staff Physicist and Coordinator of Science Facilities, collaborated closely.

Williams Astronomy students in attendance at the Keck Consortium
Student Research Symposium at Swarthmore College, September 2009

Kwitter continues her research on planetary nebulae (material ejected from dying stars similar to the sun), amassing chemical compositions for a large sample in order to understand how the chemical enrichment of the Milky Way and other spiral galaxies has proceeded over cosmic time. With support from the NSF, she and collaborators Dick Henry (U. Oklahoma) and Bruce Balick (U. Washington) are pursuing their study of planetary nebulae in the low-metallicity environments of the outer disk and halo of the Milky Way Galaxy and in the Andromeda Galaxy. They are leading an international collaboration of researchers and students in this effort. Kwitter and Henry worked with Reggie Dufour (Rice U.) on Hubble Space Telescope observations of planetary nebulae. Kwitter and her colleagues were awarded time on the 8-m Gemini North telescope on Mauna Kea, Hawaii, in October; they traveled there with senior honors student Emma Lehman to carry out the observations of M31 halo planetary nebulae.

Jay Pasachoff, Steven Souza, and Bryce Babcock collaborated on several projects that each involved student participation in expedition research, an interesting scientific question, and Federal grant support.

Pasachoff and Babcock led a team of students and other collaborators for the 22 July 2009 total solar eclipse of the sun, which they observed from Tianhuanping, China, in the mountains west of Hangzhou. Katie DuPré ’10, Sara Dwyer ’11, Caroline Ng ’11, and Charles Cao ’09 participated along with Keck Northeast Astronomy Consortium Summer Fellow Rachel Wagner-Kaiser (Vassar ’10). Marek Demianski, Visiting Professor of Astronomy; Paul Rosenthal, team doctor; and Adam Wang, Office of Information Technology, also participated on site. Babcock, Ng, and DuPré used two of our frame-transfer CCD systems named POETS (Portable Occultation, Eclipse, and Transit Systems) and twin 20-cm Celestron carbon-fiber-tube telescopes for the latest version of the oscillation experiment, which is meant to distinguish among theories of coronal heating. The team collaborated in China with Lin Lan of Hangzhou High School, Yihua Yan of the National Astronomical Observatories (Beijing), and Jin Zhu of the Beijing Planetarium. They also collaborated with Robert Lucas of the University of Sydney, who has been associated with them since the 2002 eclipse in Australia; and with John Seiradakis of the Aristotle University of Thessaloniki, who has been associated with them since the 2006 eclipse in Greece, and Aristides Voulgaris, also of Thessaloniki. Funding for the Keck Northeast Astronomy Consortium Summer Fellow came from the National Science Foundation. The work is described at <http://www.williams.edu/astronomy/eclipse/eclipse2009/index.html>.

Pasachoff, Dwyer, and Wagner-Kaiser worked especially with photography of the eclipse. Pasachoff continues to work with Miloslav Druckmüller of the Brno Institute of Technology, Czech Republic and with Vojtech Rusin and Metod Saniga of the Tatranska Lomnica Observatory of the Slovakian Academy of Sciences on analysis of high-resolution image processing, including the analysis of motions seen in the corona in the time between different sites.

Pasachoff worked with Seiradakis and Voulgaris on preparing a paper for Solar Physics about chromospheric and coronal spectra taken at the 2006 and 2008 total eclipses. The paper shows the decline in overall coronal temperature with the sunspot cycle, and provides a new way of determining the length of totality and of the flash spectrum through such spectral observations.

The team was accompanied in China by a film crew from YAP films that was making a program for National Geographic Television: Storm Worlds: Cosmic Fire. It aired in May 2010; a seven-minute clip showing the Williams team's work appears at <http://www.youtube.com/watch?v=zQbRf0fnIHI>.

Pasachoff observed the January 2010 annular eclipse of the sun from Kanyukumari, at the southern tip of India. It was his 50th solar eclipse. He worked with Janardhan Padmanabhan of the Physical Research Institute, Ahmedabad (where Pasachoff visited en route to the eclipse site) and Dale Gary of the New Jersey Institute of Technology in using the Giant Metrewave Radio Telescope near Pune, India, to observe the eclipse at a frequency of 327 MHz in the radio spectrum. Links on these are available at <http://www.williams.edu/astronomy/eclipse/eclipse2009/2009total/index.html>.

Pasachoff, Babcock, and Souza, in collaboration with their MIT colleagues, prepared for, arranged, and observed the October 9, 2009, occultation of a star by a Kuiper-belt object, one of the trans-Neptunian objects. Babcock and DuPré ’10 observed from Oahu, Hawaii; Souza was on the Big Island of Hawaii, for observations; and Pasachoff arranged observing with the Faulkes 2-m telescope of the Las Cumbres Observatory Global Telescope on Maui, Hawaii, and with a telescope at the Mt. John Observatory in New Zealand. The overall set of telescopes arranged by the MIT-Williams consortium was 21. In the event, the best data were taken from Faulkes on Maui, confirming positive observations were obtained from the Big Island of Hawaii, and close limiting observations were obtained from Oahu. Pasachoff, Babcock, Souza, and DuPré are co-authors of a resulting paper, “A Young Surface on an Old Object,” that appeared in Nature for June 17, 2010.

Pasachoff and Will Jacobson ’08, with Alphonse Sterling of NASA’s Marshall Space Flight Center as co-author, had their final paper on spicule statistics appearing in Solar Physics.

Pasachoff continued his work on transits of Mercury and Venus, collaborating with Glenn Schneider of the Steward Observatory of the University of Arizona. They are studying the total solar irradiance with Richard Willson of Columbia University, Principle Investigator of NASA’s ACRIMSAT satellite, and Roger Helizon of NASA’s Jet Propulsion Laboratory, the Project Manager of ACRIMSAT. Though Pasachoff, Schneider, and Willson had readily observed the 0.1% dip in the sun’s total irradiance from Venus’s silhouette, Mercury’s apparent area is only 1/30 that of Venus, making the chances of detection marginal. Pasachoff consulted with scientists from the other spacecraft that also measure total solar irradiance, the Variability of solar IRadiance and Gravity Oscillations (VIRGO) experiment on the European Space Agency and NASA’s Solar and Heliospheric Observatory and the Total Irradiance Monitor (TIM) experiment on NASA’s SOlar Radiation and Climate Experiment (SORCE) spacecraft. A joint paper is planned.

Pasachoff contined work in collaboration with Donald Lubowich of Hofstra University on studies of the interstellar medium, especially through considerations of the cosmic deuterium abundance.

Pasachoff served as Retiring President of the International Astronomical Union’s Commission on Education and Development <http://www.astronomyeducation.org>. He participated in the General Assembly of the International Astronomical Union held in Rio de Janeiro in August 2009. There, he became a member of the IAU’s Johannes Kepler Working Group.

Pasachoff was Chair of the International Astronomical Union’s Working Group on Solar Eclipses and also as head of a related Program Group on Public Education at the Times of Eclipses of the Commission on Education and Development. See <http://www.eclipses.info>.

Pasachoff was liaison of the American Astronomical Society to the American Association for the Advancement of Science. Pasachoff is incoming Vice-Chair and Chair-elect of the American Astronomical Society’s Historical Astronomy Division. He continued as President of Williams College’s Sigma Xi chapter and as the Williams representative to the NASA-sponsored Massachusetts Space Grant.

Pasachoff was a astronomy consultant for the McGraw-Hill Encyclopedia of Science and Technology and its yearbooks. He also continues on the Physical Science Board of World Book. He is on the Council of Advisors of the Astronomy Education Review electronic journal. See <http://aer.noao.edu/>. Pasachoff was a science book reviewer for The Key Reporter, the Phi Beta Kappa newsletter. He continues as advisor to the children’s magazine Odyssey.

Pasachoff and Golub’s second edition of their text The Solar Corona (Cambridge University Press) was published. He also worked with art-historian Roberta J. M. Olson of the New-York Historical Society.

Souza conducts the astronomy observing program, and all indoor labs and daytime observing. He hosted numerous observatory visitors, including planetarium groups, alumni, Family Days attendees, the Massachusetts Teachers Association, and student previews and prospective students. He acts as liaison with Facilities and OIT, and served on the college Instructional Technology Committee for the 2009-10 academic year.

Souza continues to maintain and improve the observatory, working with individuals in Facilities to resolve several longstanding maintenance issues. He added auto guiding to the DFM 0.6-m telescope, and is working on a new camera system to enable better solar and planetary imaging. He once again upgraded the astronomy computing facilities with trickle iMacs and with two new-model iMacs for the use of thesis students.

Souza traveled to Hilo, Hawaii in October 2009 to observe a stellar occultation by the Kuiper Belt object 2002TX300, working with Nathan Secrest, a UH undergraduate. Although an injury prevented Souza from observing with a POETS camera system as planned, Secrest made an observation using his own equipment that confirmed an event seen by collaborators on Maui. Other collaborators attempted observations of this event using the low-cost variant of POETS that Souza helped Matthew Lockhart of MIT to develop.

During the spring semester Souza began a new project intended to monitor H-alpha emission from B-type stars in open clusters. Sarah Wilson ’13 and Erin Boettcher, Haverford ’12 - a Keck Northeast Astronomy Consortium exchange student, are working with him during the summer to test the feasibility of such a program, and to establish consistent procedures for ongoing monitoring.

Souza reviewed a manuscript for the Publications of the Astronomical Society of the Pacific and three equipment proposals for the National Science Foundation.

[Colloquia are held jointly with the Physics Department. See Physics section for listings.]

Steven Souza

“Magnetic Resonance Imaging”
Guest lecture in Instrumental Methods of Analysis (CHEM 364)

Kwitter and Souza

Attended the Keck Northeast Astronomy Consortium’s faculty meeting held at Wesleyan University, June 2009
Kwitter, Souza and Pasachoff

Attended the Keck Northeast Astronomy Consortium’s student research symposium at Swarthmore College, September 2009, along with 11 Williams astronomy students
Kwitter

“Abundances of Galactic Anticenter Planetary Nebulae and the Galactic Oxygen Gradient”
co-authored with Richard B.C. Henry, Anne E. Jaskot ’08, and Bruce Balick
American Astronomical Society in Washington, D.C. January 2010
Pasachoff and art-historian Roberta J. M. Olson

Attended the meeting on the Inspiration of Astronomical Phenomena, INSAP6, for celebrating the 450^th anniversary of Galileo’s first astronomical use of the telescope, Venice, October 2009
Pasachoff

“Solar Eclipses”
SPACE, Science Popularization Association for Communicators and Educators, 2010
Nehru Museum in New Delhi, January 2010
Apejee School in suburban New Delhi, India, 2010
Pasachoff

Participated in the meeting of the American Astronomical Society in Washington, D.C., January 2010
Pasachoff

Participated in the Joint Meeting of the Solar Physics Division in Miami, FL, June 2010