Ultraviolet spectra and geometric albedos of 45 asteroids

Spectral reflectances and geometic albedos between 2300 and 3250 A are determined for 45 asteroids from data acquired by the International Ultraviolet Explorer satellite. The geometric albedos are consistently low, ranging from approximately 0.02 for C-type asteroids to approximately 0.08 for M-type asteroids. An exception is the single E-type asteroid (44 Nysa) with a geometric albedo of 0.3 at 2950 A. We find that the three major asteroid taxonomic classes persist into the UV. The taxonomic classes are distinguished primarily by their albedos, but S types are generally redder than C or M types. The first ultraviolet phase curved of asteroids are presented.