Full evolutionary models for PG 1159 stars. Implications for the helium-rich O(He) stars

<b>Aims.</b> We present full evolutionary calculations appropriate to post-AGB PG 1159 stars for a wide range of stellar masses. <b>Methods.</b> We take into account the complete evolutionary stages of PG 1159 progenitors starting from the Zero Age Main Sequence. We consider...

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Detalles Bibliográficos
Autores principales: Miller Bertolami, Marcelo Miguel, Althaus, Leandro Gabriel
Formato: Articulo
Lenguaje:Inglés
Publicado: 2006
Materias:
Ciencias Astronómicas
Stars: AGB and post-AGB
Stars: evolution
Stars: interiors
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/83265
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-83265
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Ciencias Astronómicas
Stars: AGB and post-AGB
Stars: evolution
Stars: interiors
spellingShingle Ciencias Astronómicas
Stars: AGB and post-AGB
Stars: evolution
Stars: interiors
Miller Bertolami, Marcelo Miguel
Althaus, Leandro Gabriel
Full evolutionary models for PG 1159 stars. Implications for the helium-rich O(He) stars
topic_facet Ciencias Astronómicas
Stars: AGB and post-AGB
Stars: evolution
Stars: interiors
description <b>Aims.</b> We present full evolutionary calculations appropriate to post-AGB PG 1159 stars for a wide range of stellar masses. <b>Methods.</b> We take into account the complete evolutionary stages of PG 1159 progenitors starting from the Zero Age Main Sequence. We consider the two kinds of Born Again Scenarios, the very late thermal pulse (VLTP) and the late thermal pulse (LTP), that give rise to hydrogen-deficient compositions. The location of our PG 1159 tracks in the effective temperature-gravity diagram and their comparison with previous calculations as well as the resulting surface compositions are discussed. <b>Results.</b> Our results reinforce the idea that the different abundances of 14N observed at the surface of those PG 1159 stars with undetected hydrogen is an indication that the progenitors of these stars would have evolved through a VLTP episode, where most of the hydrogen content of the remnant is burnt, or LTP, where hydrogen is not burnt but instead diluted to very low surface abundances. We derive new values for spectroscopical masses based on these models. We discuss the correlation between the presence of planetary nebulae and the 14N abundance as another indicator that 14N-rich objects should come from a VLTP episode while 14N-deficient ones should be the result of a LTP. Finally, we discuss an evolutionary scenario that could explain the existence of PG 1159 stars with unusually high helium abundances and a possible evolutionary connection between these stars and the low mass O(He) stars.
format Articulo
Articulo
author Miller Bertolami, Marcelo Miguel
Althaus, Leandro Gabriel
author_facet Miller Bertolami, Marcelo Miguel
Althaus, Leandro Gabriel
author_sort Miller Bertolami, Marcelo Miguel
title Full evolutionary models for PG 1159 stars. Implications for the helium-rich O(He) stars
title_short Full evolutionary models for PG 1159 stars. Implications for the helium-rich O(He) stars
title_full Full evolutionary models for PG 1159 stars. Implications for the helium-rich O(He) stars
title_fullStr Full evolutionary models for PG 1159 stars. Implications for the helium-rich O(He) stars
title_full_unstemmed Full evolutionary models for PG 1159 stars. Implications for the helium-rich O(He) stars
title_sort full evolutionary models for pg 1159 stars. implications for the helium-rich o(he) stars
publishDate 2006
url http://sedici.unlp.edu.ar/handle/10915/83265
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AT althausleandrogabriel fullevolutionarymodelsforpg1159starsimplicationsfortheheliumrichohestars
bdutipo_str Repositorios
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