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

Autores
Miller Bertolami, Marcelo Miguel; Córsico, Alejandro Hugo; Althaus, Leandro Gabriel
Año de publicación
2011
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
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.
Facultad de Ciencias Astronómicas y Geofísicas
Instituto de Astrofísica de La Plata
Materia
Ciencias Astronómicas
stars: evolution
stars: individual (LS IV-14116)
stars: oscillations
subdwarfs
Nivel de accesibilidad
acceso abierto
Condiciones de uso
http://creativecommons.org/licenses/by-nc-sa/4.0/
Repositorio
SEDICI (UNLP)
Institución
Universidad Nacional de La Plata
OAI Identificador
oai:sedici.unlp.edu.ar:10915/84776
Acceder
id SEDICI_7b513592754baeb3da28d64557244cdd
oai_identifier_str oai:sedici.unlp.edu.ar:10915/84776
network_acronym_str SEDICI
repository_id_str 1329
network_name_str SEDICI (UNLP)
spelling On the challenging variability of LS IV-14°116: Pulsational instabilities excited by the ε-mechanismMiller Bertolami, Marcelo MiguelCórsico, Alejandro HugoAlthaus, Leandro GabrielCiencias Astronómicasstars: evolutionstars: individual (LS IV-14116)stars: oscillationssubdwarfsWe 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.Facultad de Ciencias Astronómicas y GeofísicasInstituto de Astrofísica de La Plata2011info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfhttp://sedici.unlp.edu.ar/handle/10915/84776enginfo:eu-repo/semantics/altIdentifier/issn/2041-8205info:eu-repo/semantics/altIdentifier/doi/10.1088/2041-8205/741/1/L3info:eu-repo/semantics/openAccesshttp://creativecommons.org/licenses/by-nc-sa/4.0/Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)reponame:SEDICI (UNLP)instname:Universidad Nacional de La Platainstacron:UNLP2025-10-22T16:56:56Zoai:sedici.unlp.edu.ar:10915/84776Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-10-22 16:56:57.209SEDICI (UNLP) - Universidad Nacional de La Platafalse
dc.title.none.fl_str_mv On the challenging variability of LS IV-14°116: Pulsational instabilities excited by the ε-mechanism
title On the challenging variability of LS IV-14°116: Pulsational instabilities excited by the ε-mechanism
spellingShingle On the challenging variability of LS IV-14°116: Pulsational instabilities excited by the ε-mechanism
Miller Bertolami, Marcelo Miguel
Ciencias Astronómicas
stars: evolution
stars: individual (LS IV-14116)
stars: oscillations
subdwarfs
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
dc.creator.none.fl_str_mv Miller Bertolami, Marcelo Miguel
Córsico, Alejandro Hugo
Althaus, Leandro Gabriel
author Miller Bertolami, Marcelo Miguel
author_facet Miller Bertolami, Marcelo Miguel
Córsico, Alejandro Hugo
Althaus, Leandro Gabriel
author_role author
author2 Córsico, Alejandro Hugo
Althaus, Leandro Gabriel
author2_role author
author
dc.subject.none.fl_str_mv Ciencias Astronómicas
stars: evolution
stars: individual (LS IV-14116)
stars: oscillations
subdwarfs
topic Ciencias Astronómicas
stars: evolution
stars: individual (LS IV-14116)
stars: oscillations
subdwarfs
dc.description.none.fl_txt_mv 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.
Facultad de Ciencias Astronómicas y Geofísicas
Instituto de Astrofísica de La Plata
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.
publishDate 2011
dc.date.none.fl_str_mv 2011
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
Articulo
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://sedici.unlp.edu.ar/handle/10915/84776
url http://sedici.unlp.edu.ar/handle/10915/84776
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/issn/2041-8205
info:eu-repo/semantics/altIdentifier/doi/10.1088/2041-8205/741/1/L3
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
http://creativecommons.org/licenses/by-nc-sa/4.0/
Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
eu_rights_str_mv openAccess
rights_invalid_str_mv http://creativecommons.org/licenses/by-nc-sa/4.0/
Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
dc.format.none.fl_str_mv application/pdf
dc.source.none.fl_str_mv reponame:SEDICI (UNLP)
instname:Universidad Nacional de La Plata
instacron:UNLP
reponame_str SEDICI (UNLP)
collection SEDICI (UNLP)
instname_str Universidad Nacional de La Plata
instacron_str UNLP
institution UNLP
repository.name.fl_str_mv SEDICI (UNLP) - Universidad Nacional de La Plata
repository.mail.fl_str_mv alira@sedici.unlp.edu.ar
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score 12.982451

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