The Weak Wind Stars
Abstract
The hottest and most massive stars on the main sequence have spectral types O and B. The standard theory of line driven winds predicts that these stars possess strong stellar winds with mass-loss rates up to 10^{-5} M_⊙/yr. These predictions have been verified for the hottest O-stars by means of spectral analyses in the optical, UV, and radio range - albeit there are still uncertainties due to the effects of unknown wind inhomogeneities. However, for stars with luminosity class V (dwarfs) and subtypes between late-O and early-B the same analysis techniques yield mass-loss rates that are at least one order of magnitude below the values expected from the wind theory. Thus, there is a severe discordance, which is often referred to as ``the weak wind problem'' in the literature. Our new multi-wavelength observations and their analyses shed new light on this issue. We will present recent results from X-ray and UV spectroscopy of early B-type stars and the weak-wind O9V star μ Columbae.
- Publication:
-
Massive Stars: From alpha to Omega
- Pub Date:
- June 2013
- Bibcode:
- 2013msao.confE..49T