Radiation-driven winds of hot luminous stars

XV. Constraints on the mass–luminosity relation of central stars of planetary nebulae

¹ Institut für Astronomie und Astrophysik der Universität München, Scheinerstraße 1, 81679 München, Germany
² Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822, USA

Corresponding author: A. W. A. Pauldrach, uh10107@usm.uni-muenchen.de

Received: 2 July 2003
Accepted: 16 February 2004

Abstract

We present a new model atmosphere analysis of nine central stars of planetary nebulae. This study is based on a new generation of realistic stellar model atmospheres for hot stars; state-of-the-art, hydrodynamically consistent, spherically symmetric model atmospheres that have been shown to correctly reproduce the observed UV spectra of massive Population I O-type stars. The information provided by the wind features (terminal velocity, mass loss rate) permits to derive the physical size of each central star, from which we can derive the stellar luminosity, mass, and distance, without having to assume a relation between stellar mass and luminosity taken from the theory of stellar structure and AGB and post-AGB evolution. The results of our analysis are quite surprising: we find severe departures from the generally accepted relation between post-AGB central star mass and luminosity.