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
.jpg)
- Institución
- Universidad Nacional de La Plata
- OAI Identificador
- oai:sedici.unlp.edu.ar:10915/84776
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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:UNLP2025-09-29T11:16:06Zoai: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:13292025-09-29 11:16:06.369SEDICI (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 |
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info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Articulo http://purl.org/coar/resource_type/c_6501 info:ar-repo/semantics/articulo |
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article |
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publishedVersion |
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http://sedici.unlp.edu.ar/handle/10915/84776 |
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http://sedici.unlp.edu.ar/handle/10915/84776 |
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eng |
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eng |
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info:eu-repo/semantics/altIdentifier/issn/2041-8205 info:eu-repo/semantics/altIdentifier/doi/10.1088/2041-8205/741/1/L3 |
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openAccess |
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http://creativecommons.org/licenses/by-nc-sa/4.0/ Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) |
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