Some comments on the astrometric properties of the guide star catalog
Citations Over TimeTop 11% of 1990 papers
Abstract
The first version of the Hubble Space Telescope Guide Star Catalog has been completed and released. Consideration is given to the principal aspects of the Guide Star Catalog positional system, its systematic errors (which occur relative to a plate-based coordinate system), its north-south discontinuity, and its steep magnitude dependence for stars brighter than V less than 9 mag. Positional errors (i.e., accuracy) from plate center to edge vary from 0.5 to 1.1 arcsec in the northern celestial hemisphere and from 1.0 to 1.6 arcsec in the southern celestial hemisphere. Between V = 6 mag and V = 10 mag the positional errors decrease from 1.2 (1.9) arcsec in the north (south) to 0.6 (1.1) arcsec. Relative errors for a single star range (at 30 arcmin separation) from 0.33 to 0.76 arcsec depending upon hemisphere and magnitude.