Used almost exclusively for visual observing, the slewing accuracy of the telescope is approximately 22 arc seconds (approximately the size of the disk of the planet Jupiter) over the entire sky (180 degree slew). Accuracy of slew after snyc to a star 5 degrees away is 0.61 arcseconds.
Although the optical system normally operates at f/16, a telecompressor is available for use that reduces the f/ratio to f/8. At f/16, the field of view is only 18 minutes of arc but yields very large and bright objects. For instance, M57, the Ring Nebulae and M13, the exceptional globular cluster in Hercules, or M51, the renowned spiral galaxy, fill about 50 percent of the field of view, even with the lowest power eyepiece. Though the field elevation of the site is less than 1,000 feet, members routinely can view galaxies with rated magnitudes as faint as 15 to 16. The planets are so bright that members normally add filters to the eyepieces to reduce the intensity of the image.
The scope is housed in a 20-foot diameter dome designed and constructed by the members. The floor of the observatory is elevated approximately 3 feet off the ground to eliminate ground effects.
Adjacent to the observatory is a 24 by 24 clubhouse, which features a lounge area, full kitchen, bunkroom, and full service bath. It is heated and air-conditioned.
Member Jack Hudler wrote the computer software that controls the telescope in late 1980 when telescope computerization was in its infancy. It now employs the professional version of Tpoint software that is installed on virtually every major telescope in the world to improve pointing accuracy.
A recent update included adding TheSky astronomical databases and planetarium views of the skies. A cursor on the screen shows where in the sky the telescope is pointing. To slew to any sky object the member just points to it on the computer screen with a mouse, then activates the Slew To Object button. Within seconds the object is in the field of view of the eyepiece.
Hudler managed to tie the view on the screen to the telescopic view so accurately (1/2 an arc second), that members can even point the scope to an object and then have the software identify that object. Objects in TheSky databases include: Messier objects (110), New General Catalogue objects (8,164), IC objects (5,398), Uppsala Catalogue of Galaxies (12,940), Morphological Catalogue of Galaxies (29,981), Perek-Kohoutek Planetary objects (1,037), Zwicky Galaxies and Clusters of Galaxies (38,511), all planets, a customized list of common name objects (Horsehead, Whirlpool, Swan, Veil, etc), provisions to input any RA and Dec, all Catalogue 1 FK-5 stars, all SAO stars through Mag 8, the Hubble Guide State Catalogue (Mag 30 ) of stars.
[For a detailed review of the Lone Star Observatory slewing system, go to http://www.tpsoft.demon.co.uk/. Select the heading All about telescope pointing. Towards the end of that article you’ll find discussions on the pointing accuracy of the Palomar 200 inch, the Multiple-Mirror telescope in Arizona and our Lone Star Observatory 24-inch scope.]