2 USNOB CS ivo://archive.stsci.edu/catalogs/USNOB Space Telescope Science Institute Archive Space Telescope Science Institute Catalogs and Surveys Branch STScI Archive archive@stsci.edu Observational astronomy Surveys USNO-B is an all-sky catalog that presents positions, proper motions, magnitudes in various optical passbands, and star/galaxy estimators for 1,042,618,261 objects derived from 3,643,201,733 separate observations. The data were obtained from scans of 7435 Schmidt plates taken for the various sky surveys during the last 50 years. USNO-B1.0 is believed to provide all-sky coverage, completeness down to V = 21, 0>2 astrometric accuracy at J2000, 0.3 mag photometric accuracy in up to five colors, and 85% accuracy for distinguishing stars from nonstellar objects. A more detailed description of the construction and contents of the USNO-B1 catalog can be found in Monet et al. (2003, "The USNO-B Catalog", AJ, 125, 984), http://www.usno.navy.mil/USNO/astrometry/optical-IR-prod/usno-b1.0/resolveuid/41be0c1a4d1a8372289bad3baf27cde5. A mirror of USNOB exists in the MAST holdings and is thus available as a cone search. All available catalogs are listed at http://archive.stsci.edu/vo/mast_services.html. http://archive.stsci.edu/vo/mast_services.html Catalog Research 2 http://gsss.stsci.edu/webservices/vo/ConeSearch.aspx?CAT=USNOB& GET 1000 false 21 42 0.01 Optical