Guide Star Catalog II

WCSTools Catalogs
The GSC-2.2 Telescope Operations early release of this catalog contains positions, classifications, and magnitudes for 998,402,801 objects. The final catalog could contain twice as many objects. It is based on one-arcsecond scans of two epochs and three bandpasses of Palomar and UK Schmidt telescopes which are also available as the Digitized Sky Survey (DSS).

GSC 2.2 is magnitude limited to 18.5 in photographic F or 19.5 in photographic J., with bright objects filled in from the Tycho 2 Catalog.

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If you use GSC II information, please add the following acknowledgement:

The Guide Star Catalogue-II is a joint project of the Space Telescope Science Institute and the Osservatorio Astronomico di Torino. Space Telescope Science Institute is operated by the Association of Universities for Research in Astronomy, for the National Aeronautics and Space Administration under contract NAS5-26555. The participation of the Osservatorio Astronomico di Torino is supported by the Italian Council for Research in Astronomy. Additional support is provided by European Southern Observatory, Space Telescope European Coordinating Facility, the International GEMINI project and the European Space Agency Astrophysics Division.

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