VizieR Online Data Catalog: The Guide Star Catalog, Version 2.2 (GSC2.2) (STScI, 2001)

The GSC II is an all-sky catalog based on 1" resolution scans of the photographic Sky Survey plates, at two epochs and three bandpasses, from the Palomar and UK Schmidt telescopes (DSS). Positions, magnitudes, and classifications are produced for all objects on each plate. The objects are then loaded into the COMPASS database, where multiple observations of the same object are matched and assigned a unique name.

The GSC2.2 is a preliminary version of GSC II generated to support telescope operations at the GEMINI and VLT telescopes. The magnitude limits are 18.5 in photographic F (red) or 19.5 in photographic J (blue) or V. The parameters of the bright objects, overexposed on the Schmidt plates, are taken from the Tycho-2 (I/259) catalog. The final version (GSC 2.3), expected to be released in 2002, will also contain proper motions.

(1 data file).