The Telescope and Dome

For several years, the observatory at SUNY Stony Brook was used solely for undergraduate classes. Built in 1968, the observatory is located at the western end of the academic mall, atop the Earth and Space Sciences building. Exact coordinates are longitude 73 07'04'' W latitude 40 54' 06'' N, altitude 60 meters, time zone is +5 relative to Universal Time. The weather is not as bad as one might expect, base on statistics from 1991 through 1993 one can expect about 120 usable nights a year with about thirty of those being totally cloudless. The campus is approximately 40 miles from New York City. The location of the observatory makes it a very light polluted site. The sky brightness is 14 magnitudes per seeing disk with the seeing ranging between 3 and 5 arc seconds. This, along with the fact that the telescope drive motor is misgeared, made it difficult for the telescope to collect research data. The telescope now runs as an effective research facility. The changes are detailed below as the telescope was transformed from an old dinosaur to a more useful one.

The dome houses a 14" Celestron Schmidt-Cassegrain telescope that was installed in 1981. The telescope primary is a 14.25" diameter spherical mirror with a 60 inch radius of curvature. The secondary is slightly aspherical with a 3.5" diameter and a 17.6 inch radius of curvature. The effective focal length is 154 inches. An aspheric Schmidt corrector removes most of the spherical aberration. This telescope has some problems that make data collection arduous. The corrector plate is slightly skewed, the drive is misgeared, and the finding scope is difficult to use in the winter. The finding scope is a 30mm refractor that tends to become misaligned with the 14" when exposed to cold weather due to shrinkage of the adjusting screws. To correct for this, a 3" refractor was added to this to the 14". This addition gives a deeper finding field and has a more stable alignment. The drive motor for the telescope cannot track objects for longer than fifteen seconds before the guiding error is greater than the seeing disk size.

In 1993, a hole was drilled through the roof to a laboratory on the fourth floor. Several cables were run from a warm room to the telescope. The operator of the telescope can observe from the fourth floor, only exposing himself to the cold when finding a new target. The operation of the dome and the telescope will be discussed in later sections.