The “Mass Discrepancy” for Massive Stars: Tests of Models Using Spectroscopic Binaries

Autores
Burkholder, Valorie; Massey, Philip; Morrell, Nidia Irene
Año de publicación
1997
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Stellar evolutionary models are often used to infer a star's mass via its luminosity, but empirical checks on the accuracy of the theoretical mass-luminosity relation for very massive stars have been lacking. This is of particular concern given that modern atmosphere models yield systematically smaller masses for massive stars than do evolutionary models, with the discrepancy being a factor of 2 for Of stars. We attempt to resolve this mass discrepancy by obtaining new, high-resolution optical data on seven early-type spectroscopic binaries: V453 Cyg, HD 191201, V382 Cyg, Y Cyg, HD 206267, DH Cep, and AH Cep. Our study produces improved spectral subtypes for the components of these systems, which are crucial for evaluating their luminosities and locations in the H-R diagram. Our radial velocity study utilizes a measuring method that explicitly accounts for the effects of pair blending. We combine our new orbit solutions with existing data on inclinations and distances when available to compare the orbital masses with evolutionary models, and we find good agreement in all cases where the stars are noninteracting. (The components of V382 Cyg and DH Cep fill their Roche lobes, and in both cases we find masses substantially lower than the masses inferred from evolutionary tracks, suggesting that significant material has been lost rather than transferred. We confirm that this same trend exists for other systems drawn from the literature.) Our own data extends to only 15 M☉, although photometric inclination determinations for HD 191201 and HD 206267 should prove possible and will provide examples of higher mass systems. We briefly discuss suitable systems from the literature and conclude that orbit solutions provide good agreement with the evolutionary models to 25 M☉. Beyond this, most known binaries either fill their Roche lobes or have other complications. We also discuss five systems for which our improved data and analysis failed to yield acceptable orbit solutions: EO Aur, IU Aur, V640 Mon (Plaskett's star), LY Aur, and 29 UW CMa all remained intractable, despite improved data.
Facultad de Ciencias Astronómicas y Geofísicas
Materia
Astronomía
binaries: spectroscopic
stars: early-type
stars: evolution
stars: fundamental parameters
Nivel de accesibilidad
acceso abierto
Condiciones de uso
http://creativecommons.org/licenses/by/4.0/
Repositorio
SEDICI (UNLP)
Institución
Universidad Nacional de La Plata
OAI Identificador
oai:sedici.unlp.edu.ar:10915/140829

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network_name_str SEDICI (UNLP)
spelling The “Mass Discrepancy” for Massive Stars: Tests of Models Using Spectroscopic BinariesBurkholder, ValorieMassey, PhilipMorrell, Nidia IreneAstronomíabinaries: spectroscopicstars: early-typestars: evolutionstars: fundamental parametersStellar evolutionary models are often used to infer a star's mass via its luminosity, but empirical checks on the accuracy of the theoretical mass-luminosity relation for very massive stars have been lacking. This is of particular concern given that modern atmosphere models yield systematically smaller masses for massive stars than do evolutionary models, with the discrepancy being a factor of 2 for Of stars. We attempt to resolve this mass discrepancy by obtaining new, high-resolution optical data on seven early-type spectroscopic binaries: V453 Cyg, HD 191201, V382 Cyg, Y Cyg, HD 206267, DH Cep, and AH Cep. Our study produces improved spectral subtypes for the components of these systems, which are crucial for evaluating their luminosities and locations in the H-R diagram. Our radial velocity study utilizes a measuring method that explicitly accounts for the effects of pair blending. We combine our new orbit solutions with existing data on inclinations and distances when available to compare the orbital masses with evolutionary models, and we find good agreement in all cases where the stars are noninteracting. (The components of V382 Cyg and DH Cep fill their Roche lobes, and in both cases we find masses substantially lower than the masses inferred from evolutionary tracks, suggesting that significant material has been lost rather than transferred. We confirm that this same trend exists for other systems drawn from the literature.) Our own data extends to only 15 M☉, although photometric inclination determinations for HD 191201 and HD 206267 should prove possible and will provide examples of higher mass systems. We briefly discuss suitable systems from the literature and conclude that orbit solutions provide good agreement with the evolutionary models to 25 M☉. Beyond this, most known binaries either fill their Roche lobes or have other complications. We also discuss five systems for which our improved data and analysis failed to yield acceptable orbit solutions: EO Aur, IU Aur, V640 Mon (Plaskett's star), LY Aur, and 29 UW CMa all remained intractable, despite improved data.Facultad de Ciencias Astronómicas y Geofísicas1997-11-20info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdf328-342http://sedici.unlp.edu.ar/handle/10915/140829enginfo:eu-repo/semantics/altIdentifier/issn/0004-637Xinfo:eu-repo/semantics/altIdentifier/issn/1538-4357info:eu-repo/semantics/altIdentifier/doi/10.1086/304852info: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:UNLP2025-09-29T11:31:53Zoai:sedici.unlp.edu.ar:10915/140829Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-09-29 11:31:53.369SEDICI (UNLP) - Universidad Nacional de La Platafalse
dc.title.none.fl_str_mv The “Mass Discrepancy” for Massive Stars: Tests of Models Using Spectroscopic Binaries
title The “Mass Discrepancy” for Massive Stars: Tests of Models Using Spectroscopic Binaries
spellingShingle The “Mass Discrepancy” for Massive Stars: Tests of Models Using Spectroscopic Binaries
Burkholder, Valorie
Astronomía
binaries: spectroscopic
stars: early-type
stars: evolution
stars: fundamental parameters
title_short The “Mass Discrepancy” for Massive Stars: Tests of Models Using Spectroscopic Binaries
title_full The “Mass Discrepancy” for Massive Stars: Tests of Models Using Spectroscopic Binaries
title_fullStr The “Mass Discrepancy” for Massive Stars: Tests of Models Using Spectroscopic Binaries
title_full_unstemmed The “Mass Discrepancy” for Massive Stars: Tests of Models Using Spectroscopic Binaries
title_sort The “Mass Discrepancy” for Massive Stars: Tests of Models Using Spectroscopic Binaries
dc.creator.none.fl_str_mv Burkholder, Valorie
Massey, Philip
Morrell, Nidia Irene
author Burkholder, Valorie
author_facet Burkholder, Valorie
Massey, Philip
Morrell, Nidia Irene
author_role author
author2 Massey, Philip
Morrell, Nidia Irene
author2_role author
author
dc.subject.none.fl_str_mv Astronomía
binaries: spectroscopic
stars: early-type
stars: evolution
stars: fundamental parameters
topic Astronomía
binaries: spectroscopic
stars: early-type
stars: evolution
stars: fundamental parameters
dc.description.none.fl_txt_mv Stellar evolutionary models are often used to infer a star's mass via its luminosity, but empirical checks on the accuracy of the theoretical mass-luminosity relation for very massive stars have been lacking. This is of particular concern given that modern atmosphere models yield systematically smaller masses for massive stars than do evolutionary models, with the discrepancy being a factor of 2 for Of stars. We attempt to resolve this mass discrepancy by obtaining new, high-resolution optical data on seven early-type spectroscopic binaries: V453 Cyg, HD 191201, V382 Cyg, Y Cyg, HD 206267, DH Cep, and AH Cep. Our study produces improved spectral subtypes for the components of these systems, which are crucial for evaluating their luminosities and locations in the H-R diagram. Our radial velocity study utilizes a measuring method that explicitly accounts for the effects of pair blending. We combine our new orbit solutions with existing data on inclinations and distances when available to compare the orbital masses with evolutionary models, and we find good agreement in all cases where the stars are noninteracting. (The components of V382 Cyg and DH Cep fill their Roche lobes, and in both cases we find masses substantially lower than the masses inferred from evolutionary tracks, suggesting that significant material has been lost rather than transferred. We confirm that this same trend exists for other systems drawn from the literature.) Our own data extends to only 15 M☉, although photometric inclination determinations for HD 191201 and HD 206267 should prove possible and will provide examples of higher mass systems. We briefly discuss suitable systems from the literature and conclude that orbit solutions provide good agreement with the evolutionary models to 25 M☉. Beyond this, most known binaries either fill their Roche lobes or have other complications. We also discuss five systems for which our improved data and analysis failed to yield acceptable orbit solutions: EO Aur, IU Aur, V640 Mon (Plaskett's star), LY Aur, and 29 UW CMa all remained intractable, despite improved data.
Facultad de Ciencias Astronómicas y Geofísicas
description Stellar evolutionary models are often used to infer a star's mass via its luminosity, but empirical checks on the accuracy of the theoretical mass-luminosity relation for very massive stars have been lacking. This is of particular concern given that modern atmosphere models yield systematically smaller masses for massive stars than do evolutionary models, with the discrepancy being a factor of 2 for Of stars. We attempt to resolve this mass discrepancy by obtaining new, high-resolution optical data on seven early-type spectroscopic binaries: V453 Cyg, HD 191201, V382 Cyg, Y Cyg, HD 206267, DH Cep, and AH Cep. Our study produces improved spectral subtypes for the components of these systems, which are crucial for evaluating their luminosities and locations in the H-R diagram. Our radial velocity study utilizes a measuring method that explicitly accounts for the effects of pair blending. We combine our new orbit solutions with existing data on inclinations and distances when available to compare the orbital masses with evolutionary models, and we find good agreement in all cases where the stars are noninteracting. (The components of V382 Cyg and DH Cep fill their Roche lobes, and in both cases we find masses substantially lower than the masses inferred from evolutionary tracks, suggesting that significant material has been lost rather than transferred. We confirm that this same trend exists for other systems drawn from the literature.) Our own data extends to only 15 M☉, although photometric inclination determinations for HD 191201 and HD 206267 should prove possible and will provide examples of higher mass systems. We briefly discuss suitable systems from the literature and conclude that orbit solutions provide good agreement with the evolutionary models to 25 M☉. Beyond this, most known binaries either fill their Roche lobes or have other complications. We also discuss five systems for which our improved data and analysis failed to yield acceptable orbit solutions: EO Aur, IU Aur, V640 Mon (Plaskett's star), LY Aur, and 29 UW CMa all remained intractable, despite improved data.
publishDate 1997
dc.date.none.fl_str_mv 1997-11-20
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/10915/140829
url http://sedici.unlp.edu.ar/handle/10915/140829
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/issn/0004-637X
info:eu-repo/semantics/altIdentifier/issn/1538-4357
info:eu-repo/semantics/altIdentifier/doi/10.1086/304852
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International (CC BY 4.0)
eu_rights_str_mv openAccess
rights_invalid_str_mv http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International (CC BY 4.0)
dc.format.none.fl_str_mv application/pdf
328-342
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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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