UIT - ULTRAVIOLET OBSERVATIONS OF THE SMALL MAGELLANIC CLOUD

UIT far-ultraviolet (FUV) and near-ultraviolet (NUV) images are presented for a 40' field at the southwest end of the SMC centered near the Halpha emission object Henize 19. Photometry is obtained for 1309 stars common to the FUV (lambda(eff) = 1620 angstrom) and NUV (lambda(eff) = 2490 angstrom) images. We use UIT photometry and imagery to derive a UV color-magnitude diagram for hot field stars; confirm the consistency of low-metal-abundance stellar evolutionary models with the observations; study dust distribution in the field, finding an increase in E(B - V) from the northeast to the southwest; confirm for a large number of stars an extinction curve, like that derived by Hutchings for the SMC, which rises steeply from NUV to FUV; and derive a mass function for SMC field stars and its lack of dependence on assumed extinction curve characteristics. The mass function has a slope within the accepted range (GAMMA = -1.7 +/- 0.5) over a wide range of assumed extinction parameters, including variations of the size (+/- approximately 1.5 mag x E(B - V) in the FUV) seen in the Galaxy.