Post-AGB evolution

Of the 27 computed sequences: 17 are hydrogen-burners, and 10 are helium-burners. In only five cases was any effort made to control the phase of departure from the AGB. Lower mass models are more likely to leave the AGB burning helium, as the preceding AGB evolution has a mass-loss rate which is greatest immediately prior to a helium-shell flash.

The calculations are compared with the large observational database that has developed over recent years for the Large Magellanic Cloud. These calculations will be useful for determining the planetary nebula luminosity function, and for the study of the ultraviolet excess observed in elliptical galaxies. Addresses: Vassiliadis E. Mount Stromlo and Siding Spring Observatories, Institute of Advanced Studies, The Australian National Observatory, Private Bag, Weston Creek P.O., A.C.T. 2611, Australia Wood P.R. Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218