Stellar evolution of low- and intermediate-mass stars. II. Post-AGB evolution.

We present a set of evolutionary tracks for central stars of planetary nebulae in the range from 0.53 to 0.94M_sun_. These models are based on extensive stellar evolution calculations for initial masses between 1 and 7M_sun_ which have been carried out all the way from the main sequence through the AGB towards the stage of white dwarfs. Concerning mass losses during the post-AGB evolution we smoothly reduced the high AGB mass-loss rates and then applied rates adapted from the radiation driven wind theory. The transition time from the AGB to the central-star region depends strongly on the treatment of mass-loss beyond the AGB. Furthermore, our calculations indicate that massive central stars can fade much more slowly than hitherto assumed. It is shown that the fading time scales and the AGB history are closely connected, and that therefore the preceding mass loss on the AGB plays an important role for the post-AGB evolution.