A Two-color (U,B) Survey of the Galactic Plane: The Search Continues

Examination of the two-color photographic survey of the galactic plane taken in support of the Uhuru X-ray satellite is continuing. The original intent of the survey, taken with the Palomar 48-in Oschin Schmidt telescope, was to attempt the identification of the optical counterparts of newly detected x-ray sources. However, no optical identifications were successfully made, due in large part to the poor positional accuracy of the x-ray sources as determined by Uhuru. Visual examination of the double-exposed U and B plates did, however, produced 82 sources ranging in color from U-B = 0 to U-B = -1.5, including one cataclysmic variable (Lanning 10 = V363 Aql) and several probable white dwarfs, Be stars, etc. The potential for identification of low-luminosity stars, binary systems and old novae provided sufficient evidence to continue examination of the plates. The second catalog in the series containing 53 UV-bright sources has recently been completed and will appear in the January 1994 issue of PASP. A second cataclysmic variable (Lanning 90 = V1776 Cyg) identified during the examination of plates for the second catalog was published separately. A third catalog is in preparation, and plates are currently being scanned for a fourth catalog. We will present in this poster paper a description of the survey and related analysis, as well at the current status of the overall project.