IMAGES IN THE ROCKET ULTRAVIOLET - YOUNG CLUSTERS IN H-II REGIONS OF M83

UV images of M83 at 1540 and 2360 A reveal 18 compact sources that are associated with H II regions. E(B - V) values were estimated individually from the observed UV and optical colors and the Galactic UV extinction curve, using theoretical flux distributions. The dereddened colors are consistent with ages up to 3 × 106 yr. A maximum possible age of 6.5 × 106 yr is obtained assuming foreground reddening only. The distribution of observed colors is consistent with the Galactic reddening curve but not with enhanced far-UV extinction, as in the LMC 30 Dor curve. The Ha fluxes suggest either that dust within the H II regions absorbs up to 70% of the Lyman continuum radiation or that a similar fraction of the Ho flux is below the surface brightness detection limit. Cluster mass estimates depend on the range of stellar masses present but are probably in the range 104-105 M⊙.