ON THE MASS-DISTRIBUTION OF PLANETARY-NEBULAE CENTRAL STARS

We apply a method, described in Gorny et al. (1997), to derive the mas ses of 125 central stars of planetary nebulae (PN). This method is sel f-consistent and distance-independent. It requires the knowledge of th e nebular HP fluxes, angular radii and expansion velocities, as well a s the stellar visual magnitudes. This method is based on a simple mode l for the evolution of planetary nebulae, in which the central stars e volve according to the theoretical models of Blocker(1995) and Schonbe rner (1983). The results are dependent on the assumed total nebular ma ss. Nevertheless, for any reasonable total nebular mass distribution, we find that the range in planetary nebulae central star masses is ver y restricted: more than 80% of the objects have a central star mass be tween 0.55 and 0.65M.. We show how to convert, in this mass range, the observed PN central star mass distribution into a zero-age post-AGE s tar mass distribution.