Observed Mass Loss from Central Stars of Planetary Nebulae

Abstract

In the Introduction we recall the mass loss history of a progenitor of a planetary nebula (PN). Then we concentrate on the status of knowledge of fast winds in central stars of planetary nebulae (CSPN) : the detection and statistics, the observed edge velocities, relationships of the edge velocities with other stellar or nebular parameters. We then summarize the methods used to derive the mass loss rates associated to the fast winds, and review the determinations of the “observed” mass loss rates. The comparison with predictions from the radiation driven theory (RDT) is then discussed as well as possible lines for future improvements.