Stellar winds from massive stars - What are the REAL mass-loss rates?

Abstract

We discuss recent evidence that currently accepted mass-loss rates may need to be revised downwards, as a consequence of previously neglected ``clumping'' of the wind. New results on the radial stratification of the corresponding clumping factors are summarized. We investigate the influence of clumping on the ionization equilibrium of phosphorus, which is of major relevance when deriving constraints on the clumping factors from an analysis of the FUV PV resonance lines.