On the challenging variability of LS IV-14°116: Pulsational instabilities excited by the ε-mechanism

We investigate the pulsation driving mechanism responsible for the long-period photometric variations observed in LS IV-14°116, a subdwarf B star showing a He-enriched atmospheric composition. To this end, we perform detailed nonadiabatic pulsation computations over fully evolutionary post-He-core-f...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autores principales: Miller Bertolami, Marcelo Miguel, Córsico, Alejandro Hugo, Althaus, Leandro Gabriel
Formato: Articulo
Lenguaje:Inglés
Publicado: 2011
Materias:
Ciencias Astronómicas
stars: evolution
stars: individual (LS IV-14116)
stars: oscillations
subdwarfs
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/84776
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-84776
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: evolution
stars: individual (LS IV-14116)
stars: oscillations
subdwarfs
spellingShingle Ciencias Astronómicas
stars: evolution
stars: individual (LS IV-14116)
stars: oscillations
subdwarfs
Miller Bertolami, Marcelo Miguel
Córsico, Alejandro Hugo
Althaus, Leandro Gabriel
On the challenging variability of LS IV-14°116: Pulsational instabilities excited by the ε-mechanism
topic_facet Ciencias Astronómicas
stars: evolution
stars: individual (LS IV-14116)
stars: oscillations
subdwarfs
description We investigate the pulsation driving mechanism responsible for the long-period photometric variations observed in LS IV-14°116, a subdwarf B star showing a He-enriched atmospheric composition. To this end, we perform detailed nonadiabatic pulsation computations over fully evolutionary post-He-core-flash stellar structure models, appropriate for hot subdwarf stars at evolutionary phases previous to the He-core burning stage. We found that the variability of LS IV-14°116 can be attributed to non-radial g-mode pulsations excited by the ε-mechanism acting in the He-burning shells that appear before the star settles in the He-core burning stage. Even more interestingly, our results show that LS IV-14°116 could be the first known pulsating star in which the ε-mechanism of mode excitation is operating. Last but not the least, we find that the period range of destabilized modes is sensitive to the exact location of the burning shell, something that might help in distinguishing between the different evolutionary scenarios proposed for the formation of this star.
format Articulo
Articulo
author Miller Bertolami, Marcelo Miguel
Córsico, Alejandro Hugo
Althaus, Leandro Gabriel
author_facet Miller Bertolami, Marcelo Miguel
Córsico, Alejandro Hugo
Althaus, Leandro Gabriel
author_sort Miller Bertolami, Marcelo Miguel
title On the challenging variability of LS IV-14°116: Pulsational instabilities excited by the ε-mechanism
title_short On the challenging variability of LS IV-14°116: Pulsational instabilities excited by the ε-mechanism
title_full On the challenging variability of LS IV-14°116: Pulsational instabilities excited by the ε-mechanism
title_fullStr On the challenging variability of LS IV-14°116: Pulsational instabilities excited by the ε-mechanism
title_full_unstemmed On the challenging variability of LS IV-14°116: Pulsational instabilities excited by the ε-mechanism
title_sort on the challenging variability of ls iv-14°116: pulsational instabilities excited by the ε-mechanism
publishDate 2011
url http://sedici.unlp.edu.ar/handle/10915/84776
work_keys_str_mv AT millerbertolamimarcelomiguel onthechallengingvariabilityoflsiv14116pulsationalinstabilitiesexcitedbytheemechanism
AT corsicoalejandrohugo onthechallengingvariabilityoflsiv14116pulsationalinstabilitiesexcitedbytheemechanism
AT althausleandrogabriel onthechallengingvariabilityoflsiv14116pulsationalinstabilitiesexcitedbytheemechanism
bdutipo_str Repositorios
_version_ 1764820489173204992

Ejemplares similares