1996/06/21 by Alfred Gautschy, Gautschy, Alfred
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics (astro-ph) #FOS: Physical sciences #Gamma-ray bursts and supernovae #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9606136
9 pages, 13 separate postscript figures, full paper incl. pasted-in figures in postscript format is available from http://www.astro.unibas.ch/~gautschy/papers/dov.uu, submitted for publication in Astronomy and Astrophysics
arxiv created 1996/06/21 · openalex publication_date 1996/06/21 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
To improve the understanding of the pulsational instabilities of some of the PG1159-type pre-white dwarfs we performed detailed stability analyses on helium star evolutionary models. With the canonical chemical compositions, pulsational instabilities were encountered for all stellar masses considered (0.57, 0.63, 0.7 Msol). The blue boundary agrees satisfactorily with observations. The red edge, on the other hand, is found to extend lower temperatures than presently admitted by observers. The dependence of the pulsational instabilities on helium or even hydrogen abundance in the stellar envelopes is less stringent than emphasized hitherto. In particular, we found pulsationally unstable g-modes for model stellar envelopes which are representative for HS2324+3944, a newly discovered PG1159-star with a hydrogen abundance X of approximately 0.2 and being pulsating.