Telescope Specs and Info


The Principia Astronomical Observatory opened in Spring 1996, following extensive planning and research by Paul Robinson and his astronomy students. It benefited from the strong support of the Principia Trustees through its Chairman, Dawn Larmer. Architectural plans were drawn up by Andrew Pasterko, and the concrete structure has won strong admiration for its aesthetic appearance on campus near the Football Field. The upper deck of the Observatory is about 32 feet above the ground, and supports a 16-foot Ashdome with motorized rotation and window.
Since its opening, the Observatory has been the home of an eight-inch Celestron Telescope, a portable unit purchased in 1991 for the Principia Abroad trip to view the Total Solar Eclipse in Hawaii. Its storage space houses telescope accessories and another small telescope.


Observatory Telescope

The Principia College Observatory Telescope was installed in the Observatory on June 18, 1998. The purchase was made possible by generous contributions of many patrons, faculty, alumni, and friends. The telescope was made to our specifications by Opto-Mechanics Research, INC., Vail, AZ, and the mirror optics were ground by Don Loomis, former Chief Opticial for Kitt Peak National Laboratory. This group has provided optical systems for the finest observatories in the world, including the Hubble Space Telescope and the Keck Observatory on Mauna Kea in Hawaii.

The new telescope was selected for overall quality, robustness, and flexibility in our College situation. It should perform well into the Twenty-First Century. First priority on its use is given to classroom observation. Consistent with classroom needs, research projects are encouraged. The Observatory opens for two hours every Friday and Saturday evening during academic terms. In addition special groups visit on a prearranged basis. To make special arrangements, call 618-374-5293. General observatory announcements are made on the Observatory hotline, 618-374-5581.

The Principia Telescope features a 16-inch (0.41m) primary mirror, with Ritchey-Chretien figure for most uniform focus over the field of view.. Weighing close to one ton, it rests upon a concrete pier on the top Observatory tower deck. It is driven by two microstepper motors which respond to Comsoft's PC-TCS computer control program. Having been aligned with celestial true north, the telescope can be reliably pointed to within five arc-minutes of a desired object.

Research work at the Observatory has focused upon the international effort to verify orbital elements for minor planets. One area of interest has been objects whose orbits approach or cross that of Earth, called Near Earth Asteroids, or NEA's. As part of this effort, our Observatory has been awarded code #846 by the International Astronomical Union's Minor Planet Center (MPC) at Harvard. Another line of investigation as been minor planets which have been known for several orbits, but required more observation before being "numbered". We routinely request several objects from the MPC's OBSPLANNER service, which identifies objects requiring just a few more observations before being given a permanent designation. Observations of minor planets requires guided long exposures with sensitive cameras. Images are analyzed by an astrometric and photometric software program called ASTROMETRICA, by Herbert Raab, of Austria.