Multi-epoch <i>L</i>-band Spectroscopy of the Be Star μ Centauri Prior to Outburst

With the aim of contributing to the understanding of the disk formation process in Be stars, we pursued a one-year spectroscopic observing campaign of the Be star μ Centauri in the <i>L</i>-band, using VLT/ISAAC. We present the nine near-IR spectra we obtained in an epoch of relative pho...

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Autores: Aguayo, G., Mennickent, R. E., Granada, Anahí, Otero, S.
Formato: artículo
Estado:Versión publicada
Fecha de publicación:2018
País:Argentina
Recursos:Universidad Nacional de La Plata
Repositorio:SEDICI (UNLP)
Idioma:inglés
OAI Identifier:oai:sedici.unlp.edu.ar:10915/93705
Acesso em linha:http://sedici.unlp.edu.ar/handle/10915/93705
Access Level:acceso abierto
Palavra-chave:Astronomía
circumstellar matter
infrared: stars
stars: emission-line, Be
stars: mass-loss
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spelling Multi-epoch <i>L</i>-band Spectroscopy of the Be Star μ Centauri Prior to OutburstAguayo, G.Mennickent, R. E.Granada, AnahíOtero, S.Astronomíacircumstellar matterinfrared: starsstars: emission-line, Bestars: mass-lossWith the aim of contributing to the understanding of the disk formation process in Be stars, we pursued a one-year spectroscopic observing campaign of the Be star μ Centauri in the <i>L</i>-band, using VLT/ISAAC. We present the nine near-IR spectra we obtained in an epoch of relative photometric quiescence prior to an outburst of ΔV = 0.4 magnitude. Visual estimates during the epoch of our <i>L</i>-band spectroscopy are also presented for the first time, together with the unpublished complete visual light curve between the years 1998 and 2014. We observe significant and monotonic changes in emission line strength of Bracket-α and Pfund-γ lines relative to Humphreys lines, and also in the continuum slope. We interpret these observed changes in terms of important changes to the column density of the line emitting regions, moving from an optically thin to an optically thick stage just prior to a major outburst. For each observing date, we provide estimates for the column density and relative extension of the line emitting region. If the changes observed toward the end of our observing campaign were related to mass-loss changes from the central star, they would correspond to an increase in a factor of two in the mass of the disk in the innermost region. If related to the visual outburst observed one month later, the variability observed in our spectra would be the first detection of the early disk formation process in the <i>L</i>-band.Instituto de Astrofísica de La PlataFacultad de Ciencias Astronómicas y Geofísicas2018-10info: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/10915/93705enginfo:eu-repo/semantics/altIdentifier/url/https://iopscience.iop.org/article/10.3847/1538-3881/aad5dbinfo:eu-repo/semantics/altIdentifier/url/https://ri.conicet.gov.ar/handle/11336/82431info:eu-repo/semantics/altIdentifier/issn/0004-6256info:eu-repo/semantics/altIdentifier/doi/10.3847/1538-3881/aad5dbinfo:eu-repo/semantics/altIdentifier/hdl/11336/82431info: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:UNLP2024-05-08T12:57:20Zoai:sedici.unlp.edu.ar:10915/93705Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292024-05-08 12:57:20.592SEDICI (UNLP) - Universidad Nacional de La Platafalse
dc.title.none.fl_str_mv Multi-epoch <i>L</i>-band Spectroscopy of the Be Star μ Centauri Prior to Outburst
title Multi-epoch <i>L</i>-band Spectroscopy of the Be Star μ Centauri Prior to Outburst
spellingShingle Multi-epoch <i>L</i>-band Spectroscopy of the Be Star μ Centauri Prior to Outburst
Aguayo, G.
Astronomía
circumstellar matter
infrared: stars
stars: emission-line, Be
stars: mass-loss
title_short Multi-epoch <i>L</i>-band Spectroscopy of the Be Star μ Centauri Prior to Outburst
title_full Multi-epoch <i>L</i>-band Spectroscopy of the Be Star μ Centauri Prior to Outburst
title_fullStr Multi-epoch <i>L</i>-band Spectroscopy of the Be Star μ Centauri Prior to Outburst
title_full_unstemmed Multi-epoch <i>L</i>-band Spectroscopy of the Be Star μ Centauri Prior to Outburst
title_sort Multi-epoch <i>L</i>-band Spectroscopy of the Be Star μ Centauri Prior to Outburst
dc.creator.none.fl_str_mv Aguayo, G.
Mennickent, R. E.
Granada, Anahí
Otero, S.
author Aguayo, G.
author_facet Aguayo, G.
Mennickent, R. E.
Granada, Anahí
Otero, S.
author_role author
author2 Mennickent, R. E.
Granada, Anahí
Otero, S.
author2_role author
author
author
dc.subject.none.fl_str_mv Astronomía
circumstellar matter
infrared: stars
stars: emission-line, Be
stars: mass-loss
topic Astronomía
circumstellar matter
infrared: stars
stars: emission-line, Be
stars: mass-loss
description With the aim of contributing to the understanding of the disk formation process in Be stars, we pursued a one-year spectroscopic observing campaign of the Be star μ Centauri in the <i>L</i>-band, using VLT/ISAAC. We present the nine near-IR spectra we obtained in an epoch of relative photometric quiescence prior to an outburst of ΔV = 0.4 magnitude. Visual estimates during the epoch of our <i>L</i>-band spectroscopy are also presented for the first time, together with the unpublished complete visual light curve between the years 1998 and 2014. We observe significant and monotonic changes in emission line strength of Bracket-α and Pfund-γ lines relative to Humphreys lines, and also in the continuum slope. We interpret these observed changes in terms of important changes to the column density of the line emitting regions, moving from an optically thin to an optically thick stage just prior to a major outburst. For each observing date, we provide estimates for the column density and relative extension of the line emitting region. If the changes observed toward the end of our observing campaign were related to mass-loss changes from the central star, they would correspond to an increase in a factor of two in the mass of the disk in the innermost region. If related to the visual outburst observed one month later, the variability observed in our spectra would be the first detection of the early disk formation process in the <i>L</i>-band.
publishDate 2018
dc.date.none.fl_str_mv 2018-10
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/10915/93705
url http://sedici.unlp.edu.ar/handle/10915/93705
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/url/https://iopscience.iop.org/article/10.3847/1538-3881/aad5db
info:eu-repo/semantics/altIdentifier/url/https://ri.conicet.gov.ar/handle/11336/82431
info:eu-repo/semantics/altIdentifier/issn/0004-6256
info:eu-repo/semantics/altIdentifier/doi/10.3847/1538-3881/aad5db
info:eu-repo/semantics/altIdentifier/hdl/11336/82431
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
instacron:UNLP
instname_str Universidad Nacional de La Plata
instacron_str UNLP
institution UNLP
reponame_str SEDICI (UNLP)
collection SEDICI (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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