2007/11/15 by Orsola De Marco, De Marco, Orsola
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics (astro-ph) #Astrophysics and Star Formation Studies #FOS: Physical sciences #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.48550/arxiv.0711.2461
12 pages, 2 figures. To be published in the proceedings of the third symposium on hydrogen deficient stars. Tubingen September 2007
arxiv created 2007/11/15 · openalex publication_date 2007/11/15 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Hydrogen-deficient central stars of planetary nebula such as Wolf-Rayet and PG1159 central stars and some weak emission line stars are primarily composed of helium and carbon. This abundance is well explained by a scenario where a single post-AGB star experiences a last helium shell flash which ingests and burns, or simply dilutes, the remaining hydrogen atmosphere. But despite its success in matching the photospheric abundances of these stars, this scenario is faced with several observational challenges. A binary scenario is proposed here as a more natural way to face some of the most stringent observational constraints. In this scenario the H-rich primary in a close binary formed during a common envelope on the AGB, suffers a last helium shell flash, which results in a H-deficient primary with some of the characteristics needed to match the observations.