Oscillatory secular modes: The thermal micropulses

Aims. Stars in the narrow mass range of about 2.5 and 3.5 M ⊙ can develop a thermally unstable He-burning shell during its ignition phase. We study, from the point of view secular stability theory, these so-called thermal micropulses and investigate their properties; the thermal pulses constitute a...

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Detalles Bibliográficos
Autores principales: Gautschy, A., Althaus, Leandro Gabriel
Formato: Articulo
Lenguaje:Inglés
Publicado: 2007
Materias:
Ciencias Astronómicas
Stars: AGB and post-AGB
Stars: interiors
Stars: oscillations
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/83151
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-83151
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: interiors
Stars: oscillations
spellingShingle Ciencias Astronómicas
Stars: AGB and post-AGB
Stars: interiors
Stars: oscillations
Gautschy, A.
Althaus, Leandro Gabriel
Oscillatory secular modes: The thermal micropulses
topic_facet Ciencias Astronómicas
Stars: AGB and post-AGB
Stars: interiors
Stars: oscillations
description Aims. Stars in the narrow mass range of about 2.5 and 3.5 M ⊙ can develop a thermally unstable He-burning shell during its ignition phase. We study, from the point of view secular stability theory, these so-called thermal micropulses and investigate their properties; the thermal pulses constitute a convenient conceptual laboratory to look thoroughly into the physical properties of a helium-burning shell during the whole thermally pulsing episode. Methods. Linear stability analyses were performed on a large number of 3 M⊙ star models toward the end of their core helium-burning and the beginning of the double shell burning phase. The stellar models were not assumed to be in thermal equilibrium. Results. The thermal mircopulses - and we conjecture all other thermal pulse episodes encountered by shell burning stars - can be understood as the nonlinear finite-amplitude realization of an oscillatory secular instability that prevails during the whole thermal pulsing episode. Hence, the cyclic nature of the thermal pulses can be traced back to a linear instability concept.
format Articulo
Articulo
author Gautschy, A.
Althaus, Leandro Gabriel
author_facet Gautschy, A.
Althaus, Leandro Gabriel
author_sort Gautschy, A.
title Oscillatory secular modes: The thermal micropulses
title_short Oscillatory secular modes: The thermal micropulses
title_full Oscillatory secular modes: The thermal micropulses
title_fullStr Oscillatory secular modes: The thermal micropulses
title_full_unstemmed Oscillatory secular modes: The thermal micropulses
title_sort oscillatory secular modes: the thermal micropulses
publishDate 2007
url http://sedici.unlp.edu.ar/handle/10915/83151
work_keys_str_mv AT gautschya oscillatorysecularmodesthethermalmicropulses
AT althausleandrogabriel oscillatorysecularmodesthethermalmicropulses
bdutipo_str Repositorios
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