Mass Loss and the Origin of OBN Stars

Abstract

Mass loss rates of M> 1.5 x 10-6 M0 yr-' are found to convert a 32 M0 star into a OBN star. Rates of M > 4 x 10-6 M0 yr-1 cause the luminosity to decrease, but can produce an OBN star near the main sequence. In order for 160 to decrease significantly, it is necessary to expose material which was originally in the convective core. Subject headings: stars: abundances - stars: early-type - stars: interiors - stars: mass loss