Evidence of the evolved nature of the B[e] star MWC 137

Autores
Muratore, María Florencia; Kraus, M.; Oksala, M. E.; Arias, María Laura; Cidale, Lydia Sonia; Borges Fernandes, M.; Liermann, A.
Año de publicación
2015
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
The evolutionary phase of B[e] stars is difficult to establish due to the uncertainties in their fundamental parameters. For instance, possible classifications for the Galactic B[e] star MWC 137 include pre-main-sequence and post-main-sequence phases, with a large range in luminosity. Our goal is to clarify the evolutionary stage of this peculiar object, and to study the CO molecular component of its circumstellar medium. To this purpose, we modeled the CO molecular bands using high-resolution K-band spectra. We find that MWC 137 is surrounded by a detached cool (T = 1900 ± 100 K) and dense (N = (3 ± 1) × 1021 cm-2) ring of CO gas orbiting the star with a rotational velocity, projected to the line of sight, of 84 ± 2 km s-1. We also find that the molecular gas is enriched in the isotope 13C, excluding the classification of the star as a Herbig Be. The observed isotopic abundance ratio (12C/13C = 25 ± 2) derived from our modeling is compatible with a proto-planetary nebula, main-sequence, or supergiant evolutionary phase. However, based on some observable characteristics of MWC 137, we propose that the supergiant scenario seems to be the most plausible. Hence, we suggest that MWC 137 could be in an extremely short-lived phase, evolving from a B[e] supergiant to a blue supergiant with a bipolar ring nebula.
Facultad de Ciencias Astronómicas y Geofísicas
Materia
Ciencias Astronómicas
circumstellar matter
stars: early-type
stars: emission-line Be
stars: individual (MWC 137)
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:10915/86074

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network_name_str SEDICI (UNLP)
spelling Evidence of the evolved nature of the B[e] star MWC 137Muratore, María FlorenciaKraus, M.Oksala, M. E.Arias, María LauraCidale, Lydia SoniaBorges Fernandes, M.Liermann, A.Ciencias Astronómicascircumstellar matterstars: early-typestars: emission-line Bestars: individual (MWC 137)The evolutionary phase of B[e] stars is difficult to establish due to the uncertainties in their fundamental parameters. For instance, possible classifications for the Galactic B[e] star MWC 137 include pre-main-sequence and post-main-sequence phases, with a large range in luminosity. Our goal is to clarify the evolutionary stage of this peculiar object, and to study the CO molecular component of its circumstellar medium. To this purpose, we modeled the CO molecular bands using high-resolution K-band spectra. We find that MWC 137 is surrounded by a detached cool (T = 1900 ± 100 K) and dense (N = (3 ± 1) × 10<SUP>21</SUP> cm<SUP>-2</SUP>) ring of CO gas orbiting the star with a rotational velocity, projected to the line of sight, of 84 ± 2 km s<SUP>-1</SUP>. We also find that the molecular gas is enriched in the isotope <SUP>13</SUP>C, excluding the classification of the star as a Herbig Be. The observed isotopic abundance ratio (<SUP>12</SUP>C/<SUP>13</SUP>C = 25 ± 2) derived from our modeling is compatible with a proto-planetary nebula, main-sequence, or supergiant evolutionary phase. However, based on some observable characteristics of MWC 137, we propose that the supergiant scenario seems to be the most plausible. Hence, we suggest that MWC 137 could be in an extremely short-lived phase, evolving from a B[e] supergiant to a blue supergiant with a bipolar ring nebula.Facultad de Ciencias Astronómicas y Geofísicas2015info: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/10915/86074enginfo:eu-repo/semantics/altIdentifier/issn/0004-6256info:eu-repo/semantics/altIdentifier/doi/10.1088/0004-6256/149/1/13info: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:UNLP2025-09-29T11:17:00Zoai:sedici.unlp.edu.ar:10915/86074Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-09-29 11:17:00.307SEDICI (UNLP) - Universidad Nacional de La Platafalse
dc.title.none.fl_str_mv Evidence of the evolved nature of the B[e] star MWC 137
title Evidence of the evolved nature of the B[e] star MWC 137
spellingShingle Evidence of the evolved nature of the B[e] star MWC 137
Muratore, María Florencia
Ciencias Astronómicas
circumstellar matter
stars: early-type
stars: emission-line Be
stars: individual (MWC 137)
title_short Evidence of the evolved nature of the B[e] star MWC 137
title_full Evidence of the evolved nature of the B[e] star MWC 137
title_fullStr Evidence of the evolved nature of the B[e] star MWC 137
title_full_unstemmed Evidence of the evolved nature of the B[e] star MWC 137
title_sort Evidence of the evolved nature of the B[e] star MWC 137
dc.creator.none.fl_str_mv Muratore, María Florencia
Kraus, M.
Oksala, M. E.
Arias, María Laura
Cidale, Lydia Sonia
Borges Fernandes, M.
Liermann, A.
author Muratore, María Florencia
author_facet Muratore, María Florencia
Kraus, M.
Oksala, M. E.
Arias, María Laura
Cidale, Lydia Sonia
Borges Fernandes, M.
Liermann, A.
author_role author
author2 Kraus, M.
Oksala, M. E.
Arias, María Laura
Cidale, Lydia Sonia
Borges Fernandes, M.
Liermann, A.
author2_role author
author
author
author
author
author
dc.subject.none.fl_str_mv Ciencias Astronómicas
circumstellar matter
stars: early-type
stars: emission-line Be
stars: individual (MWC 137)
topic Ciencias Astronómicas
circumstellar matter
stars: early-type
stars: emission-line Be
stars: individual (MWC 137)
dc.description.none.fl_txt_mv The evolutionary phase of B[e] stars is difficult to establish due to the uncertainties in their fundamental parameters. For instance, possible classifications for the Galactic B[e] star MWC 137 include pre-main-sequence and post-main-sequence phases, with a large range in luminosity. Our goal is to clarify the evolutionary stage of this peculiar object, and to study the CO molecular component of its circumstellar medium. To this purpose, we modeled the CO molecular bands using high-resolution K-band spectra. We find that MWC 137 is surrounded by a detached cool (T = 1900 ± 100 K) and dense (N = (3 ± 1) × 10<SUP>21</SUP> cm<SUP>-2</SUP>) ring of CO gas orbiting the star with a rotational velocity, projected to the line of sight, of 84 ± 2 km s<SUP>-1</SUP>. We also find that the molecular gas is enriched in the isotope <SUP>13</SUP>C, excluding the classification of the star as a Herbig Be. The observed isotopic abundance ratio (<SUP>12</SUP>C/<SUP>13</SUP>C = 25 ± 2) derived from our modeling is compatible with a proto-planetary nebula, main-sequence, or supergiant evolutionary phase. However, based on some observable characteristics of MWC 137, we propose that the supergiant scenario seems to be the most plausible. Hence, we suggest that MWC 137 could be in an extremely short-lived phase, evolving from a B[e] supergiant to a blue supergiant with a bipolar ring nebula.
Facultad de Ciencias Astronómicas y Geofísicas
description The evolutionary phase of B[e] stars is difficult to establish due to the uncertainties in their fundamental parameters. For instance, possible classifications for the Galactic B[e] star MWC 137 include pre-main-sequence and post-main-sequence phases, with a large range in luminosity. Our goal is to clarify the evolutionary stage of this peculiar object, and to study the CO molecular component of its circumstellar medium. To this purpose, we modeled the CO molecular bands using high-resolution K-band spectra. We find that MWC 137 is surrounded by a detached cool (T = 1900 ± 100 K) and dense (N = (3 ± 1) × 10<SUP>21</SUP> cm<SUP>-2</SUP>) ring of CO gas orbiting the star with a rotational velocity, projected to the line of sight, of 84 ± 2 km s<SUP>-1</SUP>. We also find that the molecular gas is enriched in the isotope <SUP>13</SUP>C, excluding the classification of the star as a Herbig Be. The observed isotopic abundance ratio (<SUP>12</SUP>C/<SUP>13</SUP>C = 25 ± 2) derived from our modeling is compatible with a proto-planetary nebula, main-sequence, or supergiant evolutionary phase. However, based on some observable characteristics of MWC 137, we propose that the supergiant scenario seems to be the most plausible. Hence, we suggest that MWC 137 could be in an extremely short-lived phase, evolving from a B[e] supergiant to a blue supergiant with a bipolar ring nebula.
publishDate 2015
dc.date.none.fl_str_mv 2015
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/10915/86074
url http://sedici.unlp.edu.ar/handle/10915/86074
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/issn/0004-6256
info:eu-repo/semantics/altIdentifier/doi/10.1088/0004-6256/149/1/13
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
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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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