ULTRAVIOLET-SPECTRA AND GEOMETRIC ALBEDOS OF 45 ASTEROIDS

Spectral reflectances and geometric albedos between 2300 and 3250 Angs trom are determined for 45 asteroids from data acquired by the Interna tional Ultraviolet Explorer satellite. The geometric albedos are consi stently low, ranging from similar to 0.002 for C-type asteroids to sim ilar to 0.08 for M-type asteroids. An exception is the single E-type a steroid (33 Nysa) with a geometric albedo of 0.3 at 2950 Angstrom. 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 ultrav iolet phase curves of asteroids are presented. (C) 1994 Academic Press , Inc.