Published online by Cambridge University Press: 14 August 2015
A search to continuum magnitude B ∼ 21.5 (MB∼ −3) using a narrow band filter at λ4670å and a wide B-band filter has revealed 21 Wolf-Rayet star candidates in about half the giant Sb galaxy M31. Some weak-line WR stars, particularly WN subtypes, may have escaped detection. These numbers are compatible with the total number of luminous (i.e. massive) stars in M31. Eighteen of twenty confirmed candidate stars in M31 lie in the direction of 0B associations in the ring of prominent star formation 5–16 kpc from the center.