AGB and Post-AGB Evolution: Structural and Chemical Changes
arXiv:astro-ph/0102383 · doi:10.1007/978-94-015-9688-6_37
Abstract
Structural and chemical changes during the AGB and post-AGB evolution are discussed with respect to two recent observational and theoretical findings. On the one hand, high-resolution infrared observations revealed details of the dynamical evolution of the fragmented, bipolar dust shell around the far-evolved carbon star IRC+10216 giving evidence for rapid changes of an already PPN-like structure during the very end of the AGB evolution. On the other hand, stellar evolution calculations considering convective overshoot have shown how thermal pulses during the post-AGB stage lead to the formation of hydrogen-deficient post-AGB stars with abundance patterns consistent with those observed for Wolf-Rayet central stars.
8 pages including 4 PostScript figures; also available from http://www.mpifr-bonn.mpg.de/div/ir-interferometry/publications.html; Proceedings of "Post-AGB Objects (Proto-Planetary Nebulae) as a Phase of Stellar Evolution", R. Szczerba, R. Tylenda, S.K. Gorny (eds.), in press