IUE Observations of Early-Type Stars at High Galactic Latitudes

Abstract

High- and low-resolution IUE spectra of 14 apparently normal high-Galactic latitude B-type stars, together with visual fluxes determined from Stroemgren four-color photometry, are compared with theoretical spectra deduced from LTE model atmosphere calculations. Ten of the program stars have normal flux distributions, with only four of the stars exhibiting UV flux deficiency. For the latter, PHL 346 has been identified as a beta Cepheid variable, SB 357 is a Be-type star, and the ultraviolet flux deficiency for HD 214080 can be removed by increasing the E(B-V) from 0.09 to 0.12. In the case of HD 100340, the four-color photometry is inconsistent with the ultraviolet flux distribution, but this inconsistency vanishes when UBV photometry is employed in the analysis, implying that the uvby measurements may be in error. The normal flux distributions found for the program star provide support for their being Population I objects in the Galactic halo.