Volume 450, Number 2, May I 2006
|Page(s)||701 - 714|
|Section||Stellar structure and evolution|
|Published online||10 April 2006|
Post-AGB stars as testbeds of nucleosynthesis in AGB stars
LUTH, Observatoire de Meudon, 5 Place Jules Janssen, 92195 Meudon Cedex, France e-mail: firstname.lastname@example.org
2 N. Copernicus Astronomical Center, Rabiańska 8, 87-100 Toruń, Poland
Accepted: 30 December 2005
We construct a data base of 125 post-AGB objects (including R CrB and extreme helium stars) with published photospheric parameters (effective temperature and gravity) and chemical composition. We estimate the masses of the post-AGB stars by comparing their position in the (log , log g) plane with theoretical evolutionary tracks of different masses. We construct various diagrams, with the aim of finding clues to AGB nucleosynthesis. This is the first time that a large sample of post-AGB stars has been used in a systematic way for such a purpose and we argue that, in several respects, post-AGB stars should be more powerful than planetary nebulae to test AGB nucleosynthesis. Our main findings are that: the vast majority of objects which do not show evidence of N production from primary C have a low stellar mass (); there is no evidence that objects which did not experience 3rd dredge-up have a different stellar mass distribution than objects that did; there is clear evidence that 3rd dredge-up is more efficient at low metallicity. The sample of known post-AGB stars is likely to increase significantly in the near future thanks to the ASTRO-F and follow-up observations, making these objects even more promising as testbeds for AGB nucleosynthesis.
Key words: stars: AGB and post AGB / stars: abundances / stars: evolution / nuclear reactions, nucleosynthesis, abundances
© ESO, 2006
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.