Skymap: a new catalog of stellar data.

A new compilation of star data has been made for all known stars brighter than 9.0 mag (blue and visual), which includes approximately 255,000 stars. Tile data were obtained from several existing catalogs. Tile Smithsonian Astrophysical Observatory (SAO), AGK 3, and Henry Draper catalogs were used as sources of positions and proper motions. Magnitudes were obtained from Mermilliod, Blanco et al., Jaschek et al., and the Henry Draper catalog. Spectral types were from Jaschek, Mermilliod, Blanco, and the Henry Draper catalog. Parallaxes came from Jenkins and radial velocities from Wilson. Multiple star data were taken from the United States Naval Observatory compendium ( ) and variable star data from Kukarkin et al. Magnitude, spectral type, and position data were converted to a common system by various reduction algorithms. Tile UBV system of magnitudes, the MK spectral-type classifications, and the SAO system of positions were adopted as standards. Other parameters, such as distance and an interstellar reddening index, were derived from the source data. Errors in these derived parameters were also computed because, for many of them, the source data were incomplete or unreliable and led to large uncertainties. A description of the methods used for obtaining, converting, or calculating each data word in the new star catalog is given. Analysis of the catalog is under way but is not reported in this article. At this time, the catalog exists only on magnetic tape, but a hard-copy version is being considered. Copies of the tape are available; interested parties should contact the author. Subject headings: photometry - stars: catalogs - stars: spectral classification