26-inch Instrumentation - Astronomy at UVa

Leander McCormick Observatory 26-inch Instrumentation

In 1877 Leander J. McCormick donated a 26-inch telescope to the University, and an observatory which now bears his name was built to house it on Mount Jefferson. The primary intrument used for research was a photographic plate camera that was in regular use through the mid-1990's along with other devices stored at the observatory including an impressive array of astrometric instruments. In the last few years with most of the research being transfered to the Fan Mountain Observatory, efforts have been to transform the observatory into a modern teaching and outreach facility. New modern CCD instruments and a spectrograph have been added to the 26-inch, giving UVa students access to one of the largest teaching telescopes in the US.

Instrument	Description	Notes	Status
EYE	2-inch Eyepieces	A	Operational
ST-1001E	Direct SBIG ST-1001E CCD Camera	B	Operational
ST-8	Direct SBIG ST-8/8E CCD Camera	C	Operational
10-C Spec	OptoMechanics Model 10-C Slit Spectrograph	D	Operational
Astrovid	Astrovid 2000 High-Speed Video Camera	E	Operational
Speckle	Crane-Built Speckle Interferometer	F	Operational

NOTES

A. Currently, the primary use for eyepieces are for undergraduate telscope observing classes and for public outreach events. There are curently three eyepieces available: a 20mm Nagler, a 35mm Panoptic, and a 50mm Plössl.

B. Optical imaging may be done using an SBIG ST-1001E CCD Camera. The camera is a class 1 grade detector, single-amplifier CCD that is theromelectrically cooled. There are filter slots allowing for 2-inch square filters.

C. Optical imaging may be done using one of two SBIG ST-8 CCD cameras The cameras are a single-amplifier CCD that is theromelectrically cooled. There are filter slots allowing for 2-inch square filters.
NOTE: One of these CCDs will be used in conjunction with the 10-C spectrograph, and therefore be unavailable for imaging.

D. The 26-inch has been equipped with an Opto-Mechanics Model 10-C slit spectrograph with a Santa Barbara Instruments ST-8 CCD as a detector. The spectrograph has two slits and three gratings (240, 600, 1200 l/mm). There are manually operated Ne and Hg comparison lamps built in to the spectrograph. Both the 10-C and the ST-8 instruments were designed for use with Meade Schmidt-Cassegrain telescopes, but we have adapted them for use with the Leander McCormick Observatory 26-inch refractor.

E. The Astrovid 2000 CCD video camera's intended purpose was as the detector for the speckle interferometry system, but its light weight and simple controls also make it ideal for establishing a quick and direct video feed from the telescope. Note, however, that the video camera should not be thought of as an integrating device since the maximum exposure time is 1/60th of a second. The Astrovid is best applied to the viewing of bright objects (the moon, planets, bright stars) in real time, and the recording of high frequency phenomena (like speckles and seeing motion).

F. A speckle interferometer was designed by graduate student Jeff Crane. The system is custom build and used with the 26-inch and the Astrovid 2000 Video Camera.

Filters

The Leander McCormick Observatory has a small collection of 2-inch filters for educational uses. We have a set of standard UBVRI broad band photometry filters. However, with the chromatic aberation present in the the 26-inch refractor only the B, V and R filters find limited use. The default filter used is the V filter, primarily for single-band photometry of variable stars.

For more information, see the Leander McCormick Observatory Filters Webpage