Low-resolution IUE observations of four unreddened, 11th magnitude B stars at high galactic latitudes.

Abstract

Low-resolution IUE spectra are presented for the four faint, unreddened, high-latitude, mid-B stars Feige 40 (≡FB 72), H.O. +23°B, H.O. +41°B (≡SS II 135) and PB 166. By comparison with stars in the Heck et al. atlas, the spectra are like those of normal disc stars of Population I metallicity. This suggests that the programme stars are massive, luminous objects, which, if true, means that they are situated several kiloparsecs outside the galactic plane. Effective temperatures and upper limits on the Population I ages are derived. Radial velocities are known for two of the stars: they are consistent with stellar birth in the galactic plane followed by ejection, at high speed, to the present locations within the evolutionary lifetimes. Predictions are made for the radial velocities of the other two stars.