We have completed a survey of the closest giant spiral galaxy beyond our own for Wolf-Rayet stars, using narrow band imaging techniques (cf. Moffat and Shara 1983, Ap. J., 273, 544). About 90% of the main body of M31 has been thoroughly searched to B ≅ 21.5 (MB ≅ −3.5) to a level of emission line equivalent width We(HeII 4686 A) ≳ 60 A. We do not expect interstellar extinction to be a limiting factor in the detection of WR stars, except possibly in the localized neighborhoods of massive HII regions. The mean extinction for stars in the disk is estimated to be AB ≲ 0.9 mag. Although some weak-line WN stars will have escaped detection, the survey should be complete for WC stars.
Wolf-Rayet Stars in M31
