Optical Reference Stars for Space Surveillance: Future Plans: Latest Developments

Abstract

Abstract : The current status of existing star catalogs of relevance for Space Surveillance applications will be reviewed. Hipparcos and Tycho-2 provided reference stars with milliarcsecond (mas) accuracies at their epoch of 1991.25. During the 18 years since then, the proper motion uncertainties have reduced the accuracies significantly. Ground-based programs, such as the USNO CCD Astrograph Catalog (UCAC), now provide an all-sky, astrometrically accurate (20-70 mas) reference star catalog to 16th magnitude. The USNO-B astrometric catalog contains over a billion detections, providing astrometric positions (~200 mas) and photometry for stars down to V=21 magnitude. These catalogs and others are incorporated into the Naval Observatory Merged Astrometric Dataset (NOMAD), a 100 GB dataset containing astrometric and photometric data for about 1.1 billion stars. Numerous ground and space-based programs hold the promise of providing better future astrometric star catalogs. Pan-STARRS and similar programs will image large fractions of the observable sky every clear night, producing accurate and deep astrometric catalogs. Dedicated next generation astrometric telescopes, for example the USNO Robotic Astrometric Telescope (URAT), will extend UCAC-like astrometric accuracies to fainter stars. Space-based programs like JMAPS (brighter stars) and Gaia (fainter stars) promise to produce high accuracy, astrometric catalogs in their respective magnitude ranges.