Hubble Space Telescope Spectroscopy of OB Stars in M31
Bianchi, L.; Hutchings, J. B.; Lamers, H. J. G. L. M.; Morris, S. C.; Massey, P.
Canada, Italy, Netherlands, United States
Abstract
We have obtained UV spectra of two luminous hot stars in M31 with the Hubble Space Telescope. The stars are of late O and WN spectral type and lie on opposite sides of M31. We derive UV extinction curves for M31 which differ from both the Galaxy and the LMC. We find differences between the 15 absorbers in both lines of sight in M31 and in the Galactic halo, 77" apart. The stellar wind-riven mass loss of the stars is found to be 10 times lower than in similar Galactic stars. One star appears to be an eclipsing W-R binary.