ULTRAVIOLET FE-III LINES IN THE SPECTRA OF HIGH GALACTIC LATITUDE EARLY-TYPE STARS

Using high resolution spectral data from the International Ultraviolet Explorer satellite, we present qualitative and quantitative comparisons of blends of Fe III absorption lines in the region 1890 Angstrom less than or equal to lambda less than or equal to 1930 Angstrom for a sample of fifteen high latitude B-type and standard stars. Standard and halo stars were matched in effective temperature and surface gravity using Stromgren [c(1)] and H beta photometry, and LTE model atmosphere codes were used to investigate whether they had similar iron abundances. We conclude that while most of the halo stars have Population I iron abundances and may be young objects, one star, HD 177566, has significant iron and silicon depletions and is most probably an old, evolved star. In view of the coincidence of the atmospheric parameters of this star with those of young B-type stars, we consider a post-AGB evolutionary status to be likely for HD 177566.