Pulsating low-mass white dwarfs in the frame of new evolutionary sequences : IV. The secular rate of period change
- Autores
- Calcaferro, Leila Magdalena; Córsico, Alejandro Hugo; Althaus, Leandro Gabriel
- Año de publicación
- 2017
- Idioma
- inglés
- Tipo de recurso
- artículo
- Estado
- versión publicada
- Descripción
- Context. An increasing number of low-mass (M⋆/M⊙ ≲ 0.45) and extremely low-mass (ELM, M⋆/M⊙ ≲ 0.18−0.20) white-dwarf stars are being discovered in the field of the Milky Way. Some of these stars exhibit long-period g-mode pulsations, and are called ELMV variable stars. Also, some low-mass pre-white dwarf stars show short-period p-mode (and likely radial-mode) photometric variations, and are designated as pre-ELMV variable stars. The existence of these new classes of pulsating white dwarfs and pre-white dwarfs opens the prospect of exploring the binary formation channels of these low-mass white dwarfs through asteroseismology. Aims. We aim to present a theoretical assessment of the expected temporal rates of change of periods (Π) for such stars, based on fully evolutionary low-mass He-core white dwarf and pre-white dwarf models. Methods. Our analysis is based on a large set of adiabatic periods of radial and nonradial pulsation modes computed on a suite of low-mass He-core white dwarf and pre-white dwarf models with masses ranging from 0.1554 to 0.4352 M⊙, which were derived by computing the non-conservative evolution of a binary system consisting of an initially 1 M⊙ ZAMS star and a 1.4 M⊙ neutron star companion. Results. We computed the secular rates of period change of radial (ℓ = 0) and nonradial (ℓ = 1,2) g and p modes for stellar models representative of ELMV and pre-ELMV stars, as well as for stellar objects that are evolving just before the occurrence of CNO flashes at the early cooling branches. We find that the theoretically expected magnitude of Π of g modes for pre-ELMVs is by far larger than for ELMVs. In turn, Π of g modes for models evolving before the occurrence of CNO flashes are larger than the maximum values of the rates of period change predicted for pre-ELMV stars. Regarding p and radial modes, we find that the larger absolute values of Π correspond to pre-ELMV models. Conclusions. We conclude that any eventual measurement of a rate of period change for a given pulsating low-mass pre-white dwarf or white dwarf star could shed light about its evolutionary status. Also, in view of the systematic difficulties in the spectroscopic classification of stars of the ELM Survey, an eventual measurement of Π could help to confirm that a given pulsating star is an authentic low-mass white dwarf and not a star from another stellar population.
Instituto de Astrofísica de La Plata - Materia
-
Ciencias Astronómicas
Asteroseismology
Stars: evolution
Stars: interiors
Stars: oscillations
Stars: variables: general
White dwarfs - Nivel de accesibilidad
- acceso abierto
- Condiciones de uso
- http://creativecommons.org/licenses/by/4.0/
- Repositorio
- Institución
- Universidad Nacional de La Plata
- OAI Identificador
- oai:sedici.unlp.edu.ar:10915/87483
Ver los metadatos del registro completo
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Pulsating low-mass white dwarfs in the frame of new evolutionary sequences : IV. The secular rate of period changeCalcaferro, Leila MagdalenaCórsico, Alejandro HugoAlthaus, Leandro GabrielCiencias AstronómicasAsteroseismologyStars: evolutionStars: interiorsStars: oscillationsStars: variables: generalWhite dwarfsContext. An increasing number of low-mass (M⋆/M⊙ ≲ 0.45) and extremely low-mass (ELM, M⋆/M⊙ ≲ 0.18−0.20) white-dwarf stars are being discovered in the field of the Milky Way. Some of these stars exhibit long-period g-mode pulsations, and are called ELMV variable stars. Also, some low-mass pre-white dwarf stars show short-period p-mode (and likely radial-mode) photometric variations, and are designated as pre-ELMV variable stars. The existence of these new classes of pulsating white dwarfs and pre-white dwarfs opens the prospect of exploring the binary formation channels of these low-mass white dwarfs through asteroseismology. Aims. We aim to present a theoretical assessment of the expected temporal rates of change of periods (Π) for such stars, based on fully evolutionary low-mass He-core white dwarf and pre-white dwarf models. Methods. Our analysis is based on a large set of adiabatic periods of radial and nonradial pulsation modes computed on a suite of low-mass He-core white dwarf and pre-white dwarf models with masses ranging from 0.1554 to 0.4352 M⊙, which were derived by computing the non-conservative evolution of a binary system consisting of an initially 1 M⊙ ZAMS star and a 1.4 M⊙ neutron star companion. Results. We computed the secular rates of period change of radial (ℓ = 0) and nonradial (ℓ = 1,2) g and p modes for stellar models representative of ELMV and pre-ELMV stars, as well as for stellar objects that are evolving just before the occurrence of CNO flashes at the early cooling branches. We find that the theoretically expected magnitude of Π of g modes for pre-ELMVs is by far larger than for ELMVs. In turn, Π of g modes for models evolving before the occurrence of CNO flashes are larger than the maximum values of the rates of period change predicted for pre-ELMV stars. Regarding p and radial modes, we find that the larger absolute values of Π correspond to pre-ELMV models. Conclusions. We conclude that any eventual measurement of a rate of period change for a given pulsating low-mass pre-white dwarf or white dwarf star could shed light about its evolutionary status. Also, in view of the systematic difficulties in the spectroscopic classification of stars of the ELM Survey, an eventual measurement of Π could help to confirm that a given pulsating star is an authentic low-mass white dwarf and not a star from another stellar population.Instituto de Astrofísica de La Plata2017-04info: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/10915/87483enginfo:eu-repo/semantics/altIdentifier/issn/0004-6361info:eu-repo/semantics/altIdentifier/doi/10.1051/0004-6361/201630376info:eu-repo/semantics/reference/hdl/10915/81916info:eu-repo/semantics/reference/hdl/10915/105304info:eu-repo/semantics/reference/hdl/10915/147709info:eu-repo/semantics/reference/hdl/10915/87090info:eu-repo/semantics/reference/hdl/10915/147747info:eu-repo/semantics/openAccesshttp://creativecommons.org/licenses/by/4.0/Creative Commons Attribution 4.0 International (CC BY 4.0)reponame:SEDICI (UNLP)instname:Universidad Nacional de La Platainstacron:UNLP2025-09-29T11:17:14Zoai:sedici.unlp.edu.ar:10915/87483Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-09-29 11:17:15.122SEDICI (UNLP) - Universidad Nacional de La Platafalse |
dc.title.none.fl_str_mv |
Pulsating low-mass white dwarfs in the frame of new evolutionary sequences : IV. The secular rate of period change |
title |
Pulsating low-mass white dwarfs in the frame of new evolutionary sequences : IV. The secular rate of period change |
spellingShingle |
Pulsating low-mass white dwarfs in the frame of new evolutionary sequences : IV. The secular rate of period change Calcaferro, Leila Magdalena Ciencias Astronómicas Asteroseismology Stars: evolution Stars: interiors Stars: oscillations Stars: variables: general White dwarfs |
title_short |
Pulsating low-mass white dwarfs in the frame of new evolutionary sequences : IV. The secular rate of period change |
title_full |
Pulsating low-mass white dwarfs in the frame of new evolutionary sequences : IV. The secular rate of period change |
title_fullStr |
Pulsating low-mass white dwarfs in the frame of new evolutionary sequences : IV. The secular rate of period change |
title_full_unstemmed |
Pulsating low-mass white dwarfs in the frame of new evolutionary sequences : IV. The secular rate of period change |
title_sort |
Pulsating low-mass white dwarfs in the frame of new evolutionary sequences : IV. The secular rate of period change |
dc.creator.none.fl_str_mv |
Calcaferro, Leila Magdalena Córsico, Alejandro Hugo Althaus, Leandro Gabriel |
author |
Calcaferro, Leila Magdalena |
author_facet |
Calcaferro, Leila Magdalena 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 Asteroseismology Stars: evolution Stars: interiors Stars: oscillations Stars: variables: general White dwarfs |
topic |
Ciencias Astronómicas Asteroseismology Stars: evolution Stars: interiors Stars: oscillations Stars: variables: general White dwarfs |
dc.description.none.fl_txt_mv |
Context. An increasing number of low-mass (M⋆/M⊙ ≲ 0.45) and extremely low-mass (ELM, M⋆/M⊙ ≲ 0.18−0.20) white-dwarf stars are being discovered in the field of the Milky Way. Some of these stars exhibit long-period g-mode pulsations, and are called ELMV variable stars. Also, some low-mass pre-white dwarf stars show short-period p-mode (and likely radial-mode) photometric variations, and are designated as pre-ELMV variable stars. The existence of these new classes of pulsating white dwarfs and pre-white dwarfs opens the prospect of exploring the binary formation channels of these low-mass white dwarfs through asteroseismology. Aims. We aim to present a theoretical assessment of the expected temporal rates of change of periods (Π) for such stars, based on fully evolutionary low-mass He-core white dwarf and pre-white dwarf models. Methods. Our analysis is based on a large set of adiabatic periods of radial and nonradial pulsation modes computed on a suite of low-mass He-core white dwarf and pre-white dwarf models with masses ranging from 0.1554 to 0.4352 M⊙, which were derived by computing the non-conservative evolution of a binary system consisting of an initially 1 M⊙ ZAMS star and a 1.4 M⊙ neutron star companion. Results. We computed the secular rates of period change of radial (ℓ = 0) and nonradial (ℓ = 1,2) g and p modes for stellar models representative of ELMV and pre-ELMV stars, as well as for stellar objects that are evolving just before the occurrence of CNO flashes at the early cooling branches. We find that the theoretically expected magnitude of Π of g modes for pre-ELMVs is by far larger than for ELMVs. In turn, Π of g modes for models evolving before the occurrence of CNO flashes are larger than the maximum values of the rates of period change predicted for pre-ELMV stars. Regarding p and radial modes, we find that the larger absolute values of Π correspond to pre-ELMV models. Conclusions. We conclude that any eventual measurement of a rate of period change for a given pulsating low-mass pre-white dwarf or white dwarf star could shed light about its evolutionary status. Also, in view of the systematic difficulties in the spectroscopic classification of stars of the ELM Survey, an eventual measurement of Π could help to confirm that a given pulsating star is an authentic low-mass white dwarf and not a star from another stellar population. Instituto de Astrofísica de La Plata |
description |
Context. An increasing number of low-mass (M⋆/M⊙ ≲ 0.45) and extremely low-mass (ELM, M⋆/M⊙ ≲ 0.18−0.20) white-dwarf stars are being discovered in the field of the Milky Way. Some of these stars exhibit long-period g-mode pulsations, and are called ELMV variable stars. Also, some low-mass pre-white dwarf stars show short-period p-mode (and likely radial-mode) photometric variations, and are designated as pre-ELMV variable stars. The existence of these new classes of pulsating white dwarfs and pre-white dwarfs opens the prospect of exploring the binary formation channels of these low-mass white dwarfs through asteroseismology. Aims. We aim to present a theoretical assessment of the expected temporal rates of change of periods (Π) for such stars, based on fully evolutionary low-mass He-core white dwarf and pre-white dwarf models. Methods. Our analysis is based on a large set of adiabatic periods of radial and nonradial pulsation modes computed on a suite of low-mass He-core white dwarf and pre-white dwarf models with masses ranging from 0.1554 to 0.4352 M⊙, which were derived by computing the non-conservative evolution of a binary system consisting of an initially 1 M⊙ ZAMS star and a 1.4 M⊙ neutron star companion. Results. We computed the secular rates of period change of radial (ℓ = 0) and nonradial (ℓ = 1,2) g and p modes for stellar models representative of ELMV and pre-ELMV stars, as well as for stellar objects that are evolving just before the occurrence of CNO flashes at the early cooling branches. We find that the theoretically expected magnitude of Π of g modes for pre-ELMVs is by far larger than for ELMVs. In turn, Π of g modes for models evolving before the occurrence of CNO flashes are larger than the maximum values of the rates of period change predicted for pre-ELMV stars. Regarding p and radial modes, we find that the larger absolute values of Π correspond to pre-ELMV models. Conclusions. We conclude that any eventual measurement of a rate of period change for a given pulsating low-mass pre-white dwarf or white dwarf star could shed light about its evolutionary status. Also, in view of the systematic difficulties in the spectroscopic classification of stars of the ELM Survey, an eventual measurement of Π could help to confirm that a given pulsating star is an authentic low-mass white dwarf and not a star from another stellar population. |
publishDate |
2017 |
dc.date.none.fl_str_mv |
2017-04 |
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/10915/87483 |
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dc.language.none.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
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info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International (CC BY 4.0) |
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openAccess |
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http://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International (CC BY 4.0) |
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