Racoon Run

Racoon Run is the name of my backyard observatory in Pleasanton, California (121.8481 W, 37.6550 N) located about 30 miles (48 km) east of San Francisco at an elevation of 528 feet (161 m) above sea level.  Night skies suffer from significant light pollution with only magnitude 4.4 stars observable to the naked eye on the darkest nights.  While the observatory is officially designated G61 by the International Astronomical Union it is named after the curious nocturnal visitors who like to peer over the walls at the monitor and blinking red lights.

The observatory is equipped with a Celestron 14” SCT telescope on an Astro Physics 1200GTO german equatorial mount.  The mount rests on an 18’ diameter concrete pier anchored in over 3 tons of concrete.  The observatory itself is of my own clamshell design with the floor constructed of 2”x 6” joists 12” apart overlain with ¾” thick plywood and isolated from the concrete pier so as to not conduct any vibrations to the telescope.  The walls of the observatory are made of 2”x4” ’s on 16” centers with considerable diagonal cross bracing for structural rigidity.  The clamshell roof sections are made of 2”x4” frames with 2”x2” bracing and ½” thick plywood.  Both roof sections are sufficiently heavy that motorized screw jacks are used for their movement.  Although the observatory is a fairly heavy structure, the floor is chained to bolts embedded deep into the concrete footing as a final safety measure to prevent movement from extreme winds.

Since 2002, I have focused on working with professional astronomers on the search for, and study of, planets orbiting around other suns, otherwise known as exoplanets.  

Because such research requires the precise measurement of light from stars, the telescope is equipped with an extremely sensitive cooled CCD camera from Santa Barbara Instruments Group, their ST-10XME.  The light reaching the CCD camera is filtered using an Optec IFS filter wheel along with an Optec TCF-S precision focuser.

A separate, smaller telescope is mounted to the main 14” SCT and is used for either wide field imaging or guiding using a Santa Barbara Instruments Group ST-402ME cooled CCD camera. 

The combination of the AP1200GTO along with the SBIG 10-XME allows the tracking of stars to within 2 arc-seconds positional accuracy and the measurement of the brightness of stars to less than 0.5%.  2 arc-seconds is equivalent to the thickness of a U.S. quarter observed at a distance of almost 600 feet.

Contact

Ron Bissinger

Email: racrun (at) comcast (dot) net 

This page was last updated on 07/06/06.