is mainly used for Star Occultations by the Moon. Successors to USNO-A, etc Stars evolve and move over time, making catalogues evolving, impermanent databases at even the most rigorous levels of production. The USNO catalogues are the most current and widely used astrometric catalogues available at present, and include USNO products such as USNO-B (the successor to USNO-A), NOMAD, UCAC and others in production or narrowly released. Some users may see specialized catalogues (more recent versions of the above), tailored catalogues, interferometrically-produced catalogues, dynamic catalogues, and those with updated positions, motions, colors, and improved errors. Catalogue data is continually collected at the Naval Observatory dark-sky facility, NOFS; and the latest refined, updated catalogues are reduced and produced by NOFS and the USNO. See the USNO Catalog and Image Servers for more information and access. See also List of astronomical catalogues Messier object New General Catalogue of Nebulae and Clusters of Stars Astrometry Star chart Fixed stars References Bibliography Further reading External links Current Public, High-Metric Accuracy Star Catalogues produced by USNO SAO – Smithsonian Astrophysical Observatory Star Catalog NASA Astronomy Data Center Centre de Données astronomiques de Strasbourg Sloan Digital Sky Survey IAU FAQ on "Naming Stars" Astrometry Catalogue