Interpretation of the UV spectrum of some stars with little reddening

Abstract

The spectrum of five stars is analysed and explained by the superimposition of two components. One is the extinction of the direct starlight, with an extinction coefficient A which varies as the inverse of the wavelength across all the UV. This linear dependence of extinction upon the inverse of wavelength prolongs to the UV the well known relation which exist in the optical between extinction and wavelength. The second component is an additional feature, superimposed on the extincted direct starlight. This feature is interpreted as starlight scattered by dust at close angular distance to the star, into the beam of the observation.