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
RID-UNRN (UNRN)
Institución
Universidad Nacional de Río Negro
OAI Identificador
oai:rid.unrn.edu.ar:20.500.12049/8987

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network_acronym_str RIDUNRN
repository_id_str 4369
network_name_str RID-UNRN (UNRN)
spelling 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
rights_invalid_str_mv https://creativecommons.org/licenses/by-nc-sa/4.0/
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv EDP Sciences
publisher.none.fl_str_mv EDP Sciences
dc.source.none.fl_str_mv reponame:RID-UNRN (UNRN)
instname:Universidad Nacional de Río Negro
reponame_str RID-UNRN (UNRN)
collection RID-UNRN (UNRN)
instname_str Universidad Nacional de Río Negro
repository.name.fl_str_mv RID-UNRN (UNRN) - Universidad Nacional de Río Negro
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