MIT Reports to the President 1996-97

GEORGE R. WALLACE, JR., ASTROPHYSICAL OBSERVATORY

The George R. Wallace, Jr., Astrophysical Observatory is a teaching and research observatory located in Westford, Massachusetts. Its facilities consist of a 24-inch telescope, a 16-inch telescope, several 14- and 8-inch telescopes, a 5.5-inch astrograph, and a building that houses a workshop, darkroom, computer facility, and observers' quarters. Instruments used during the past year include a portable high-speed CCD occultation system, several small CCD systems, conventional photometers, photographic cameras, and a high-resolution spectrograph. The SNAPSHOT high-speed dual-CCD photometer, in service since 1984, has been retired and plans are being formulated for a modern replacement. Work is continuing to improve the optics of the 24-inch telescope, and a low-resolution spectrograph has been prototyped for the smaller telescopes.

Professor James Elliot continued his duties as Observatory Director. Principal Research Scientist Heidi Hammel assisted with site management and telescope scheduling, with the help of Research Specialist Richard Meserole. Mr. Michael Person has served as a part-time Technical Assistant for making observations, helping with observatory maintenance and training students. Steve McDonald continued his part-time work on software and computer management. Other staff (usually students) are coordinated through research programs. Undergraduates working on the spectrograph project (Lisa Kwok) and instrument design (Paul Collins) participated in NSF's Research Experiences for Undergraduates (REU) program, as did the summer students (Shaida Bouramand, Adam Einarsen, Edgar Gonzalez, Lorraine Hertzog, Eric Nielsen, Rosa Villastrigo).

Last year, course 8.287J-12.410J (Observational Techniques of Optical Astronomy) drew 14 students, who used the Wallace facilities for a variety of astronomical projects, including observations of the total lunar eclipse that occurred in September, 1996. An additional 32 students in subject 12S23/12.409 (Observing the Stars and Planets, the first subject number distinguishes first-year vs. upperclass registrants) used the Observatory for laboratory work. Informal field trips were offered for courses 12.401 (Beyond the Solar System; 14 students) and 12S22 (Hands-on Astronomy; 8 students), as was an observing session for freshmen last fall. An open house held during MIT's 1997 Independent Activities Period attracted over 30 people (mostly undergraduates, though faculty and staff from other departments came).

Mr. McDonald, Mr. Person, and the summer students used the 24-inch to obtain astrometric CCD data for Pluto, Neptune's moon Triton, and the stars fields through which they will move during the next decade. These data will being used to identify stars that these bodies will occult so that observations can be carried out with telescopes that would happen to lie in the path where an occultation will be visible. These occultation candidates will be of particular importance for NASA's Stratospheric Observatory for Infrared Astronomy (SOFIA--a 747SP that will house a 2.5-m telescope and begin operations in 2001), which can get to the center of virtually any occultation path. The occultation data will be used to investigate how the thin N2 atmospheres of Pluto and Triton respond to changes in season and distance from the sun.

Prof. Elliot, Dr. Hammel, Mr. Collins, and Mr. Einarsen collaborated with Prof. Schechter in beginning the design of a CCD camera for the Magellan telescopes in Chile for which MIT has a 10% share of the observing time. The instrument would permanently occupy a Nasmyth port on one of the telescopes and would be always accessible for opportunity observations (such as supernovae and occultations) and synoptic observations that require only a small amount of time per night. Hence Prof. Schechter has dubbed the instrument MANIAC (MIT Auxiliary Nasmyth Instantly Accessible Camera).

Meg Golden and Mr. Person carried out CCD imaging observations of Comet Hale-Bopp during the fall and spring, using filters selected to isolate the dust and ion tails of the comet. They also participated in a cooperative effort to observe a stellar occultation by the comet in the western US in October, 1996.

Mr. McDonald, Mr. Person, and students initiated a program to search for large, slowly moving objects that may be part of the Kuiper Belt population in the outer solar system, and Dr. Slivan continued a project of imaging objects from the Messier Catalog.

James L. Elliot

MIT Reports to the President 1996-97