Be and Bn stars: Balmer discontinuity and stellar-class relationship
- Autores
- Cochetti, Yanina; Zorec, Juan; Cidale, Lydia S.; Arias, Maria L.; Aidelman, Yael; Torres, Andrea F.; Fremat, Yves; Granada, Anahi
- Año de publicación
- 2020
- Idioma
- inglés
- Tipo de recurso
- artículo
- Estado
- versión publicada
- Descripción
- Fil: Cochetti, Yanina. Departamento de Espectroscopía Estelar, Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, La Plata; Argentina
Fil: Zorec, Juan. Sorbonne Université, CNRS, UPMC, UMR 7095, Institut d’Astrophysique de Paris, 98 bis bd. Arago, 75014 Paris; France.
Fil: Cidale, Lydia. Departamento de Espectroscopía Estelar, Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, La Plata; Argentina. Instituto de Astrofísica de La Plata, CCT-La Plata, CONICET-UNLP, Paseo del Bosque s/n, CP 1900, La Plata, Buenos Aires; Argentina.
Fil: Arias, Maria Laura. Departamento de Espectroscopía Estelar, Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, La Plata; Argentina. Instituto de Astrofísica de La Plata, CCT-La Plata, CONICET-UNLP, Paseo del Bosque s/n, CP 1900, La Plata, Buenos Aires; Argentina.
Fil: Aidelman, Yael. Departamento de Espectroscopía Estelar, Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, La Plata; Argentina.
Fil: Torres, Andrea F. Departamento de Espectroscopía Estelar, Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, La Plata; Argentina. Instituto de Astrofísica de La Plata, CCT-La Plata, CONICET-UNLP, Paseo del Bosque s/n, CP 1900, La Plata, Buenos Aires; Argentina.
Fil: Frémat, Yves. Royal Observatory of Belgium, 3 Av. Circulaire, 1180 Bruxelles; Belgium 5 Laboratorio de Procesamiento de Señales Aplicadas y Computación de Alto Rendimiento, Sede Andina, Universidad Nacional de RIo Negro, Mitre 630, San Carlos de Bariloche, R8400AHN Río Negro, Argentina
Fil: Aidelman, Y. , A. F. Torres1,3 Fil: Granada, Anahi. Laboratorio de Procesamiento de Señales Aplicadas y Computación de Alto Rendimiento, Sede Andina, Universidad Nacional de RIo Negro, Mitre 630, San Carlos de Bariloche, R8400AHN Río Negro, Argentina
Fil: Granada, Anahi. Universidad Nacional de RIo Negro. Laboratorio de Procesamiento de Señales Aplicadas y Computación de Alto Rendimiento. Río Negro; Argentina
Context. A significant number of Be stars show a second Balmer discontinuity (sBD) attributed to an extended circumstellar envelope (CE). The fast rotational velocity of Be stars undoubtedly plays a significant role in the formation of the CE. However, Bn stars, which are also B-type rapidly rotating stars, do not all present clear evidence of being surrounded by circumstellar material. Aims. We aim to characterize the populations of Be and Bn stars, and discuss the appearance of the sBD as a function of the stellar parameters. We expect to find new indices characterizing the properties of CEs in Be stars and properties relating Be and Bn stars. Methods. We obtained low- and high-resolution spectra of a sample of Be and Bn stars, derived stellar parameters, characterized the sBD, and measured the emission in the Hα line. Results. Correlations of the aspect and intensity of the sBD and the emission in the Hα line with the stellar parameters and the V sin i are presented. Some Bn stars exhibit the sBD in absorption, which may indicate the presence of rather dense CEs. Six Bn stars show emission in the Hα line, so they are reclassified as Be stars. The sBD in emission appears in Be stars with V sin i ≲ 250 km s−1, and in absorption in both Be and Bn stars with V sin i ≳ 50 km s−1. Low-mass Be and Bn stars share the same region in the Hertzsprung-Russell diagram. The distributions of rotational to critical velocity ratios of Be and Bn stars corresponding to the current stellar evolutionary stage are similar, while distributions inferred for the zero-age main sequence have different skewness. Conclusions. We found emission in the Hα line and signs of a CE in some Bn stars, which motivated us to think that Bn and Be stars probably belong to the same population. It should be noted that some of the most massive Bn stars could display the Be phenomenon at any time. The similarities found among Be and Bn stars deserve to be more deeply pursued.
Contexto. Un numero significativo de las estrellas Be muestran un segundo salto de Balmer (sBD) atribuida a una envoltura circumestelar extendida.. - Materia
-
Ciencias Exactas y Naturales
circumstellar matter
stars: emission-line, Be
stars: fundamental parameters
Ciencias Exactas y Naturales - Nivel de accesibilidad
- acceso abierto
- Condiciones de uso
- https://creativecommons.org/licenses/by-nc-sa/4.0/
- Repositorio
- Institución
- Universidad Nacional de Río Negro
- OAI Identificador
- oai:rid.unrn.edu.ar:20.500.12049/8987
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Be and Bn stars: Balmer discontinuity and stellar-class relationshipCochetti, YaninaZorec, JuanCidale, Lydia S.Arias, Maria L.Aidelman, YaelTorres, Andrea F.Fremat, YvesGranada, AnahiCiencias Exactas y Naturalescircumstellar matterstars: emission-line, Bestars: fundamental parametersCiencias Exactas y NaturalesFil: Cochetti, Yanina. Departamento de Espectroscopía Estelar, Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, La Plata; ArgentinaFil: Zorec, Juan. Sorbonne Université, CNRS, UPMC, UMR 7095, Institut d’Astrophysique de Paris, 98 bis bd. Arago, 75014 Paris; France.Fil: Cidale, Lydia. Departamento de Espectroscopía Estelar, Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, La Plata; Argentina. Instituto de Astrofísica de La Plata, CCT-La Plata, CONICET-UNLP, Paseo del Bosque s/n, CP 1900, La Plata, Buenos Aires; Argentina.Fil: Arias, Maria Laura. Departamento de Espectroscopía Estelar, Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, La Plata; Argentina. Instituto de Astrofísica de La Plata, CCT-La Plata, CONICET-UNLP, Paseo del Bosque s/n, CP 1900, La Plata, Buenos Aires; Argentina.Fil: Aidelman, Yael. Departamento de Espectroscopía Estelar, Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, La Plata; Argentina.Fil: Torres, Andrea F. Departamento de Espectroscopía Estelar, Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, La Plata; Argentina. Instituto de Astrofísica de La Plata, CCT-La Plata, CONICET-UNLP, Paseo del Bosque s/n, CP 1900, La Plata, Buenos Aires; Argentina.Fil: Frémat, Yves. Royal Observatory of Belgium, 3 Av. Circulaire, 1180 Bruxelles; Belgium 5 Laboratorio de Procesamiento de Señales Aplicadas y Computación de Alto Rendimiento, Sede Andina, Universidad Nacional de RIo Negro, Mitre 630, San Carlos de Bariloche, R8400AHN Río Negro, ArgentinaFil: Aidelman, Y. , A. F. Torres1,3 Fil: Granada, Anahi. Laboratorio de Procesamiento de Señales Aplicadas y Computación de Alto Rendimiento, Sede Andina, Universidad Nacional de RIo Negro, Mitre 630, San Carlos de Bariloche, R8400AHN Río Negro, ArgentinaFil: Granada, Anahi. Universidad Nacional de RIo Negro. Laboratorio de Procesamiento de Señales Aplicadas y Computación de Alto Rendimiento. Río Negro; ArgentinaContext. A significant number of Be stars show a second Balmer discontinuity (sBD) attributed to an extended circumstellar envelope (CE). The fast rotational velocity of Be stars undoubtedly plays a significant role in the formation of the CE. However, Bn stars, which are also B-type rapidly rotating stars, do not all present clear evidence of being surrounded by circumstellar material. Aims. We aim to characterize the populations of Be and Bn stars, and discuss the appearance of the sBD as a function of the stellar parameters. We expect to find new indices characterizing the properties of CEs in Be stars and properties relating Be and Bn stars. Methods. We obtained low- and high-resolution spectra of a sample of Be and Bn stars, derived stellar parameters, characterized the sBD, and measured the emission in the Hα line. Results. Correlations of the aspect and intensity of the sBD and the emission in the Hα line with the stellar parameters and the V sin i are presented. Some Bn stars exhibit the sBD in absorption, which may indicate the presence of rather dense CEs. Six Bn stars show emission in the Hα line, so they are reclassified as Be stars. The sBD in emission appears in Be stars with V sin i ≲ 250 km s−1, and in absorption in both Be and Bn stars with V sin i ≳ 50 km s−1. Low-mass Be and Bn stars share the same region in the Hertzsprung-Russell diagram. The distributions of rotational to critical velocity ratios of Be and Bn stars corresponding to the current stellar evolutionary stage are similar, while distributions inferred for the zero-age main sequence have different skewness. Conclusions. We found emission in the Hα line and signs of a CE in some Bn stars, which motivated us to think that Bn and Be stars probably belong to the same population. It should be noted that some of the most massive Bn stars could display the Be phenomenon at any time. The similarities found among Be and Bn stars deserve to be more deeply pursued.Contexto. Un numero significativo de las estrellas Be muestran un segundo salto de Balmer (sBD) atribuida a una envoltura circumestelar extendida..EDP Sciences2020-01-30info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfCochetti et al. (2020) Be and Bn stars: Balmer discontinuity and stellar-class relationship. Astronomy and Astrophysics; 634; 1-29.0004-6361https://www.aanda.org/articles/aa/full_html/2020/02/aa36444-19/aa36444-19.htmlhttp://rid.unrn.edu.ar/handle/20.500.12049/8987https://doi.org/10.1051/0004-6361/201936444enghttps://www.aanda.org/634Astronomy and Astrophysicsinfo:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/4.0/reponame:RID-UNRN (UNRN)instname:Universidad Nacional de Río Negro2025-09-29T14:29:11Zoai:rid.unrn.edu.ar:20.500.12049/8987instacron:UNRNInstitucionalhttps://rid.unrn.edu.ar/jspui/Universidad públicaNo correspondehttps://rid.unrn.edu.ar/oai/snrdrid@unrn.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:43692025-09-29 14:29:11.81RID-UNRN (UNRN) - Universidad Nacional de Río Negrofalse |
dc.title.none.fl_str_mv |
Be and Bn stars: Balmer discontinuity and stellar-class relationship |
title |
Be and Bn stars: Balmer discontinuity and stellar-class relationship |
spellingShingle |
Be and Bn stars: Balmer discontinuity and stellar-class relationship Cochetti, Yanina Ciencias Exactas y Naturales circumstellar matter stars: emission-line, Be stars: fundamental parameters Ciencias Exactas y Naturales |
title_short |
Be and Bn stars: Balmer discontinuity and stellar-class relationship |
title_full |
Be and Bn stars: Balmer discontinuity and stellar-class relationship |
title_fullStr |
Be and Bn stars: Balmer discontinuity and stellar-class relationship |
title_full_unstemmed |
Be and Bn stars: Balmer discontinuity and stellar-class relationship |
title_sort |
Be and Bn stars: Balmer discontinuity and stellar-class relationship |
dc.creator.none.fl_str_mv |
Cochetti, Yanina Zorec, Juan Cidale, Lydia S. Arias, Maria L. Aidelman, Yael Torres, Andrea F. Fremat, Yves Granada, Anahi |
author |
Cochetti, Yanina |
author_facet |
Cochetti, Yanina Zorec, Juan Cidale, Lydia S. Arias, Maria L. Aidelman, Yael Torres, Andrea F. Fremat, Yves Granada, Anahi |
author_role |
author |
author2 |
Zorec, Juan Cidale, Lydia S. Arias, Maria L. Aidelman, Yael Torres, Andrea F. Fremat, Yves Granada, Anahi |
author2_role |
author author author author author author author |
dc.subject.none.fl_str_mv |
Ciencias Exactas y Naturales circumstellar matter stars: emission-line, Be stars: fundamental parameters Ciencias Exactas y Naturales |
topic |
Ciencias Exactas y Naturales circumstellar matter stars: emission-line, Be stars: fundamental parameters Ciencias Exactas y Naturales |
dc.description.none.fl_txt_mv |
Fil: Cochetti, Yanina. Departamento de Espectroscopía Estelar, Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, La Plata; Argentina Fil: Zorec, Juan. Sorbonne Université, CNRS, UPMC, UMR 7095, Institut d’Astrophysique de Paris, 98 bis bd. Arago, 75014 Paris; France. Fil: Cidale, Lydia. Departamento de Espectroscopía Estelar, Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, La Plata; Argentina. Instituto de Astrofísica de La Plata, CCT-La Plata, CONICET-UNLP, Paseo del Bosque s/n, CP 1900, La Plata, Buenos Aires; Argentina. Fil: Arias, Maria Laura. Departamento de Espectroscopía Estelar, Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, La Plata; Argentina. Instituto de Astrofísica de La Plata, CCT-La Plata, CONICET-UNLP, Paseo del Bosque s/n, CP 1900, La Plata, Buenos Aires; Argentina. Fil: Aidelman, Yael. Departamento de Espectroscopía Estelar, Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, La Plata; Argentina. Fil: Torres, Andrea F. Departamento de Espectroscopía Estelar, Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, La Plata; Argentina. Instituto de Astrofísica de La Plata, CCT-La Plata, CONICET-UNLP, Paseo del Bosque s/n, CP 1900, La Plata, Buenos Aires; Argentina. Fil: Frémat, Yves. Royal Observatory of Belgium, 3 Av. Circulaire, 1180 Bruxelles; Belgium 5 Laboratorio de Procesamiento de Señales Aplicadas y Computación de Alto Rendimiento, Sede Andina, Universidad Nacional de RIo Negro, Mitre 630, San Carlos de Bariloche, R8400AHN Río Negro, Argentina Fil: Aidelman, Y. , A. F. Torres1,3 Fil: Granada, Anahi. Laboratorio de Procesamiento de Señales Aplicadas y Computación de Alto Rendimiento, Sede Andina, Universidad Nacional de RIo Negro, Mitre 630, San Carlos de Bariloche, R8400AHN Río Negro, Argentina Fil: Granada, Anahi. Universidad Nacional de RIo Negro. Laboratorio de Procesamiento de Señales Aplicadas y Computación de Alto Rendimiento. Río Negro; Argentina Context. A significant number of Be stars show a second Balmer discontinuity (sBD) attributed to an extended circumstellar envelope (CE). The fast rotational velocity of Be stars undoubtedly plays a significant role in the formation of the CE. However, Bn stars, which are also B-type rapidly rotating stars, do not all present clear evidence of being surrounded by circumstellar material. Aims. We aim to characterize the populations of Be and Bn stars, and discuss the appearance of the sBD as a function of the stellar parameters. We expect to find new indices characterizing the properties of CEs in Be stars and properties relating Be and Bn stars. Methods. We obtained low- and high-resolution spectra of a sample of Be and Bn stars, derived stellar parameters, characterized the sBD, and measured the emission in the Hα line. Results. Correlations of the aspect and intensity of the sBD and the emission in the Hα line with the stellar parameters and the V sin i are presented. Some Bn stars exhibit the sBD in absorption, which may indicate the presence of rather dense CEs. Six Bn stars show emission in the Hα line, so they are reclassified as Be stars. The sBD in emission appears in Be stars with V sin i ≲ 250 km s−1, and in absorption in both Be and Bn stars with V sin i ≳ 50 km s−1. Low-mass Be and Bn stars share the same region in the Hertzsprung-Russell diagram. The distributions of rotational to critical velocity ratios of Be and Bn stars corresponding to the current stellar evolutionary stage are similar, while distributions inferred for the zero-age main sequence have different skewness. Conclusions. We found emission in the Hα line and signs of a CE in some Bn stars, which motivated us to think that Bn and Be stars probably belong to the same population. It should be noted that some of the most massive Bn stars could display the Be phenomenon at any time. The similarities found among Be and Bn stars deserve to be more deeply pursued. Contexto. Un numero significativo de las estrellas Be muestran un segundo salto de Balmer (sBD) atribuida a una envoltura circumestelar extendida.. |
description |
Fil: Cochetti, Yanina. Departamento de Espectroscopía Estelar, Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, La Plata; Argentina |
publishDate |
2020 |
dc.date.none.fl_str_mv |
2020-01-30 |
dc.type.none.fl_str_mv |
info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion http://purl.org/coar/resource_type/c_6501 info:ar-repo/semantics/articulo |
format |
article |
status_str |
publishedVersion |
dc.identifier.none.fl_str_mv |
Cochetti et al. (2020) Be and Bn stars: Balmer discontinuity and stellar-class relationship. Astronomy and Astrophysics; 634; 1-29. 0004-6361 https://www.aanda.org/articles/aa/full_html/2020/02/aa36444-19/aa36444-19.html http://rid.unrn.edu.ar/handle/20.500.12049/8987 https://doi.org/10.1051/0004-6361/201936444 |
identifier_str_mv |
Cochetti et al. (2020) Be and Bn stars: Balmer discontinuity and stellar-class relationship. Astronomy and Astrophysics; 634; 1-29. 0004-6361 |
url |
https://www.aanda.org/articles/aa/full_html/2020/02/aa36444-19/aa36444-19.html http://rid.unrn.edu.ar/handle/20.500.12049/8987 https://doi.org/10.1051/0004-6361/201936444 |
dc.language.none.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
https://www.aanda.org/ 634 Astronomy and Astrophysics |
dc.rights.none.fl_str_mv |
info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by-nc-sa/4.0/ |
eu_rights_str_mv |
openAccess |
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https://creativecommons.org/licenses/by-nc-sa/4.0/ |
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application/pdf |
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EDP Sciences |
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EDP Sciences |
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reponame:RID-UNRN (UNRN) instname:Universidad Nacional de Río Negro |
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