Previous abstract Next abstract
Session 65 - Stars and Their Progeny: Outflows and Inflows.
Invited session, Tuesday, January 14
We have known that the radiatively driven winds of OB stars are inhomogeneous and variable for more than 20 years. For the past fifteen years, studies of these winds have concentrated on the nature and origin of the inhomogeneities. One of the critical questions has been whether these inhomgeneities form spontaneously somewhere in the wind or are produced by hydrodynamic phenomena, i.e.\/, nonradial pulsation, or magnetic structures rooted in the photosphere --- the photosphere-wind connection. I will give a brief review of the development of this work and describe recent observational results from a number of groups. These have shown that the inhomogeneities in the winds of a number of stars are modulated by the star's rotation. There is good statistical evidence, and in at least one case, direct evidence that the inhomogeneities extend inward to the photosphere. Some observations seem to require an explanation in terms of nonradial pulsation, while others seem more consistent with an ordered magnetic field model. However, there are aspects of the observations that are inconsistent with either model. Clearly there is a lot of work to do before we will understand the inhomogeneities and their impact on the interpretation of OB star spectra.
Program listing for Tuesday