The peculiar UV and optical spectrum of the LMC supergiant HD 269216.

Abstract

Low resolution IUE UV and optical observations are presented of HD 269216, the visually brightest member of the LH 39 association in the LMC. Although the UV and optical line spectra are broadly consistent with a B 8 Ia spectral type for HD 269216, the classification is complicated by several discrepancies. The observed UV continuum flux distribution is much shallower than evident for "normal" late B supergiants, with no pronounced Balmer jump observed in HD 269216. Broad emission lines of hydrogen, with for example a FWHM of Hβ~650 km s^-1^ and possible He I emission are peculiarities in the optical spectrum. We estimate a stellar luminosity log (L_*_ /L_sun_)~5.4, which places HD 269216 in the same location in the H-R diagram as R71 in minimum state. The two stars are compared, and we suggest that HD 269216 warrants further monitoring as a possible S Dor-type variable.