Publications

The primary effort of the Catalogs and Surveys Branch of the Space Telescope Science Institute has been the construction of the Guide Star Catalog, both GSC-I and GSC-II. To support photometric calibration of these catalogs, CASB produced the Guide Star Photometric Catalog (GSPC-I) and now in collabortation with Osservatorio Astronomico di Torino are producing its extension GSPC II.

GSPC I is an all-sky set of photoelectrically determined BV sequences in the magnitude range from 9 to 15, generally near the centers of the fields of the GSC-I plates.

GSPC II is generally an extension of GSPC I sequences to V=19 in (B), V and R passbands based on CCD photometry. Its purpose is the calibration of the GSC-II. New northern sequences are being added to support the POSS-II currently in production and the first release (624 sequences) is now available to the public through data access. These sequences represent about one third of the total number of GSPC-II target fields. Our present efforts are focusing on quality control of the remainder of the in-house data, and on (re-)observations of the missing sequences, with the primary goal of publishing photometric calibrators for the entire sky in (B), V, and R passbands.