Properties of atmospheres and winds of H-deficient central stars and related objects
Abstract
According to latest results presented at this workshop, it appears that the surface chemistry of hydrogen-deficient post-AGB stars can now be explained by evolutionary calculations involving a late He-shell flash. A quantitative comparison of theoretical predictions with observed element abundances can eventually constrain details of this evolutionary scenario. I will emphasize here the diverse chemical compositions observed in H-deficient post-AGB stars, which call for an explanation. The abundance patterns vary from almost pure helium atmospheres to hydrogen- and helium-free atmospheres, with a rich choice of compositions in between, involving rather different mixtures of H, He, and CNO.
- Publication:
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Astrophysics and Space Science
- Pub Date:
- January 2001
- Bibcode:
- 2001Ap&SS.275...27W