Notes. Note that, like stellar radii determined from the measured flux, the so-called “observed” mass loss rates depend sensitively on the assumed distance (see text). ^P from Puls et al. (2006). ^C from Cohen et al. (2010); the sensitive dependence of the mass loss rate on the assumed abundances has been extensively discussed by the authors. ^R from Pauldrach et al. (1994); the value given is based on observed radio flux values (Abbott et al. 1980 and Abbott et al. 1985) and obtained by using the formula by Wright & Barlow (1975) for bound-free and free-free emission.