The peculiar emission-line supergiant HD 37836.

Abstract

The luminous emission-line star HD 37836 of the LMC has been studied using high-dispersion spectra in the UV and in the optical. In addition, IUE low-dispersion spectra and UBVRIJHKL photometry have been used to study the energy distribution. The emission-line spectrum of the star is very peculiar. Its UV absorption-line spectrum is more normal and indicates that HD 37836 is a late O type supergiant. Specifically, strong stellar-wind lines with an edge velocity of ≈2400 km s^-1 have been found. The most likely explanation for the variety of velocities which are found appears to be a disk surrounding the star. It is shown that the continuum energy distribution is in agreement with the presence of a disk. The two LMC stars HDE 269445 and Hen S131 have similar energy distributions and emission-line spectra and may thus represent other cases of luminous, hot supergiants surrounded by gaseous disks.