Recent Enhancements to and Future Plans for the SKY2000 Star Catalog

Volume 29 number 2 (2001)

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Christopher B. Sande

Computer Sciences Corporation 7700 Hubble Drive Lanham-Seabrook, MD 20706

Wayne H. Warren Jr.

Raytheon Technical Services Company NASA Goddard Space Flight Center Greenbelt, MD 20771

David A. Tracewell

NASA Goddard Space Flight Center Greenbelt, MD 20771

Abstract

Our continuing efforts to improve the NASA SKY2000 satellite attitude determination star catalog, previously known as SKYMAP, to make it into a modern, high-quality comprehensive source of stellar data, have allowed us to complete Version 3 of the SKY2000 catalog (2000 June). The present version of the catalog contains 299,160 entries and is reasonably complete to visual magnitude 9. As with previous versions of the SKY2000 and SKYMAP catalogs, the most important data in the catalog are astrometry and photometry, because this information is essential for spacecraft attitude determination and control. Accurate information on multiplicity, spectral type and luminosity class, and variability are also required to predict what the star trackers will detect. The SKY2000 Version 3 catalog marks the global replacement of the Henry Draper (HD) spectral type data, as well as the global replacement of the photovisual (ptv) and photographic (ptg) magnitude data. During this process, 4,684 entries had HD or HD Extension (HDE) identifiers added, for a total of 210,062 entries with HD/HDE identifiers. A planned global replacement of variable star names/identifiers and variability data was not carried out because of resource constraints, but 311 variable star names/identifiers were added during analysis, bringing the total number of entries with variable star names or identifiers to 2,575. The next planned update to the SKY2000 catalog will include a global replacement of variable star names/identifiers and variability data. Catalogs to be utilized will include, but are not limited to, the General Catalogue of Variable Stars (GCVS) (Kholopov et al. 1995) and the New Catalogue of Suspected Variable Stars (NSV) (Kukarkin et al. 1982). Completion of this updated version of the SKY2000 catalog is anticipated in Spring, 2001. We intend eventually to utilize the AAVSO database to incorporate the highest quality data periods and amplitudes, particularly for long period variables, but this may not be possible for the next enhancement. This paper describes the current status after recent enhancements of the SKY2000 catalog and outlines plans for future improvements. This edition (SKY2000, version 3) and future editions of the catalog will be made available at Goddard’s Flight Dynamics Web site: http://cheli.gsfc.nasa.gov/dist/attitude/skymap.html.