New insights into the nature of the peculiar star θ Carinae
- Autores
- Hubrig, S.; Briquet, M.; Morel, T.; Schöller, M.; Gonzalez, Jorge Federico; De Cat, P.
- Año de publicación
- 2008
- Idioma
- inglés
- Tipo de recurso
- artículo
- Estado
- versión publicada
- Descripción
- θ Context. Carinae belongs to a group of peculiar early-type stars (OBN) with enhanced nitrogen and carbon deficiency. It is also known as a binary system, but it is not clear yet whether the chemical anomalies can be explained by mass transfer between the two components. On the basis of the previously reported spectral variability of a few metal lines it may be expected that Car possesses a weak magnetic field.Aims. A study of the physical nature of this hot massive binary which is furthermore a well-known blue straggler lying ~2 mag above the turnoff of the young open cluster IC 2602 is important to understand the origin of its strong chemical anomalies.Methods. We acquired high resolution spectroscopic and low resolution spectropolarimetric observations to achieve the following goals: a) to improve the orbital parameters to allow a more in-depth discussion on the possibility of mass transfer in the binary system; b) to carry out a non-local thermodynamic equilibrium (NLTE) abundance analysis; and c) to search for the presence of a magnetic field. Results. The study of the radial velocities using CORALIE spectra allowed us to significantly improve the orbital parameters. A comparative NLTE abundance analysis was undertaken for Car and two other early B-type stars with recently detected magnetic fields, τ Sco and ξ1 CMa. The analysis revealed significantly different abundance patterns: a one-order-of-magnitude nitrogen overabundance and carbon depletion was found in Car, while the oxygen abundance is roughly solar. For the stars ξ1 CMa and τ Sco the carbon abundance is solar and, while an N excess is also detected, it is of much smaller amplitude (0.4-0.6 dex). Such an N overabundance is typical of the values already found for other slowly-rotating (magnetic) B-type dwarfs. For Car, we attribute instead the chemical peculiarities to a past episode of mass transfer between the two binary components. The results of the search for a magnetic field using FORS 1 at the VLT consisting of 26 measurements over a time span of ~1.2 h are rather inconclusive: only few measurements have a significance level of 3. Although we detect a periodicity of the order of ~8.8 min in the dataset involving the measurements on all hydrogen Balmer lines with the exception of the Hα and H lines, these results have to be confirmed by additional time-resolved magnetic field observations.
Fil: Hubrig, S.. European Southern Observatory Chile; Chile
Fil: Briquet, M.. Katholieke Universiteit Leuven; Bélgica
Fil: Morel, T.. Katholieke Universiteit Leuven; Bélgica. Université de Liège; Bélgica
Fil: Schöller, M.. European Southern Observatory Chile; Chile
Fil: Gonzalez, Jorge Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Complejo Astronómico "El Leoncito". Universidad Nacional de Córdoba. Complejo Astronómico "El Leoncito". Universidad Nacional de la Plata. Complejo Astronómico "El Leoncito". Universidad Nacional de San Juan. Complejo Astronómico "El Leoncito"; Argentina
Fil: De Cat, P.. Koninklijke Sterrenwacht van België; Bélgica - Materia
-
STARS: ABUNDANCES
STARS: ATMOSPHERES
STARS: BINARIES: SPECTROSCOPIC
STARS: EARLY-TYPE
STARS: FUNDAMENTAL PARAMETERS
STARS: MAGNETIC FIELDS - Nivel de accesibilidad
- acceso abierto
- Condiciones de uso
- https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
- Repositorio
- Institución
- Consejo Nacional de Investigaciones Científicas y Técnicas
- OAI Identificador
- oai:ri.conicet.gov.ar:11336/214862
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oai:ri.conicet.gov.ar:11336/214862 |
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3498 |
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CONICET Digital (CONICET) |
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New insights into the nature of the peculiar star θ CarinaeHubrig, S.Briquet, M.Morel, T.Schöller, M.Gonzalez, Jorge FedericoDe Cat, P.STARS: ABUNDANCESSTARS: ATMOSPHERESSTARS: BINARIES: SPECTROSCOPICSTARS: EARLY-TYPESTARS: FUNDAMENTAL PARAMETERSSTARS: MAGNETIC FIELDShttps://purl.org/becyt/ford/1.3https://purl.org/becyt/ford/1θ Context. Carinae belongs to a group of peculiar early-type stars (OBN) with enhanced nitrogen and carbon deficiency. It is also known as a binary system, but it is not clear yet whether the chemical anomalies can be explained by mass transfer between the two components. On the basis of the previously reported spectral variability of a few metal lines it may be expected that Car possesses a weak magnetic field.Aims. A study of the physical nature of this hot massive binary which is furthermore a well-known blue straggler lying ~2 mag above the turnoff of the young open cluster IC 2602 is important to understand the origin of its strong chemical anomalies.Methods. We acquired high resolution spectroscopic and low resolution spectropolarimetric observations to achieve the following goals: a) to improve the orbital parameters to allow a more in-depth discussion on the possibility of mass transfer in the binary system; b) to carry out a non-local thermodynamic equilibrium (NLTE) abundance analysis; and c) to search for the presence of a magnetic field. Results. The study of the radial velocities using CORALIE spectra allowed us to significantly improve the orbital parameters. A comparative NLTE abundance analysis was undertaken for Car and two other early B-type stars with recently detected magnetic fields, τ Sco and ξ1 CMa. The analysis revealed significantly different abundance patterns: a one-order-of-magnitude nitrogen overabundance and carbon depletion was found in Car, while the oxygen abundance is roughly solar. For the stars ξ1 CMa and τ Sco the carbon abundance is solar and, while an N excess is also detected, it is of much smaller amplitude (0.4-0.6 dex). Such an N overabundance is typical of the values already found for other slowly-rotating (magnetic) B-type dwarfs. For Car, we attribute instead the chemical peculiarities to a past episode of mass transfer between the two binary components. The results of the search for a magnetic field using FORS 1 at the VLT consisting of 26 measurements over a time span of ~1.2 h are rather inconclusive: only few measurements have a significance level of 3. Although we detect a periodicity of the order of ~8.8 min in the dataset involving the measurements on all hydrogen Balmer lines with the exception of the Hα and H lines, these results have to be confirmed by additional time-resolved magnetic field observations.Fil: Hubrig, S.. European Southern Observatory Chile; ChileFil: Briquet, M.. Katholieke Universiteit Leuven; BélgicaFil: Morel, T.. Katholieke Universiteit Leuven; Bélgica. Université de Liège; BélgicaFil: Schöller, M.. European Southern Observatory Chile; ChileFil: Gonzalez, Jorge Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Complejo Astronómico "El Leoncito". Universidad Nacional de Córdoba. Complejo Astronómico "El Leoncito". Universidad Nacional de la Plata. Complejo Astronómico "El Leoncito". Universidad Nacional de San Juan. Complejo Astronómico "El Leoncito"; ArgentinaFil: De Cat, P.. Koninklijke Sterrenwacht van België; BélgicaEDP Sciences2008-12info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/octet-streamapplication/pdfhttp://hdl.handle.net/11336/214862Hubrig, S.; Briquet, M.; Morel, T.; Schöller, M.; Gonzalez, Jorge Federico; et al.; New insights into the nature of the peculiar star θ Carinae; EDP Sciences; Astronomy and Astrophysics; 488; 1; 12-2008; 287-2960004-6361CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/doi/10.1051/0004-6361:200809972info:eu-repo/semantics/altIdentifier/url/https://www.aanda.org/articles/aa/abs/2008/34/aa09972-08/aa09972-08.htmlinfo:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-29T10:10:40Zoai:ri.conicet.gov.ar:11336/214862instacron:CONICETInstitucionalhttp://ri.conicet.gov.ar/Organismo científico-tecnológicoNo correspondehttp://ri.conicet.gov.ar/oai/requestdasensio@conicet.gov.ar; lcarlino@conicet.gov.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:34982025-09-29 10:10:40.415CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse |
dc.title.none.fl_str_mv |
New insights into the nature of the peculiar star θ Carinae |
title |
New insights into the nature of the peculiar star θ Carinae |
spellingShingle |
New insights into the nature of the peculiar star θ Carinae Hubrig, S. STARS: ABUNDANCES STARS: ATMOSPHERES STARS: BINARIES: SPECTROSCOPIC STARS: EARLY-TYPE STARS: FUNDAMENTAL PARAMETERS STARS: MAGNETIC FIELDS |
title_short |
New insights into the nature of the peculiar star θ Carinae |
title_full |
New insights into the nature of the peculiar star θ Carinae |
title_fullStr |
New insights into the nature of the peculiar star θ Carinae |
title_full_unstemmed |
New insights into the nature of the peculiar star θ Carinae |
title_sort |
New insights into the nature of the peculiar star θ Carinae |
dc.creator.none.fl_str_mv |
Hubrig, S. Briquet, M. Morel, T. Schöller, M. Gonzalez, Jorge Federico De Cat, P. |
author |
Hubrig, S. |
author_facet |
Hubrig, S. Briquet, M. Morel, T. Schöller, M. Gonzalez, Jorge Federico De Cat, P. |
author_role |
author |
author2 |
Briquet, M. Morel, T. Schöller, M. Gonzalez, Jorge Federico De Cat, P. |
author2_role |
author author author author author |
dc.subject.none.fl_str_mv |
STARS: ABUNDANCES STARS: ATMOSPHERES STARS: BINARIES: SPECTROSCOPIC STARS: EARLY-TYPE STARS: FUNDAMENTAL PARAMETERS STARS: MAGNETIC FIELDS |
topic |
STARS: ABUNDANCES STARS: ATMOSPHERES STARS: BINARIES: SPECTROSCOPIC STARS: EARLY-TYPE STARS: FUNDAMENTAL PARAMETERS STARS: MAGNETIC FIELDS |
purl_subject.fl_str_mv |
https://purl.org/becyt/ford/1.3 https://purl.org/becyt/ford/1 |
dc.description.none.fl_txt_mv |
θ Context. Carinae belongs to a group of peculiar early-type stars (OBN) with enhanced nitrogen and carbon deficiency. It is also known as a binary system, but it is not clear yet whether the chemical anomalies can be explained by mass transfer between the two components. On the basis of the previously reported spectral variability of a few metal lines it may be expected that Car possesses a weak magnetic field.Aims. A study of the physical nature of this hot massive binary which is furthermore a well-known blue straggler lying ~2 mag above the turnoff of the young open cluster IC 2602 is important to understand the origin of its strong chemical anomalies.Methods. We acquired high resolution spectroscopic and low resolution spectropolarimetric observations to achieve the following goals: a) to improve the orbital parameters to allow a more in-depth discussion on the possibility of mass transfer in the binary system; b) to carry out a non-local thermodynamic equilibrium (NLTE) abundance analysis; and c) to search for the presence of a magnetic field. Results. The study of the radial velocities using CORALIE spectra allowed us to significantly improve the orbital parameters. A comparative NLTE abundance analysis was undertaken for Car and two other early B-type stars with recently detected magnetic fields, τ Sco and ξ1 CMa. The analysis revealed significantly different abundance patterns: a one-order-of-magnitude nitrogen overabundance and carbon depletion was found in Car, while the oxygen abundance is roughly solar. For the stars ξ1 CMa and τ Sco the carbon abundance is solar and, while an N excess is also detected, it is of much smaller amplitude (0.4-0.6 dex). Such an N overabundance is typical of the values already found for other slowly-rotating (magnetic) B-type dwarfs. For Car, we attribute instead the chemical peculiarities to a past episode of mass transfer between the two binary components. The results of the search for a magnetic field using FORS 1 at the VLT consisting of 26 measurements over a time span of ~1.2 h are rather inconclusive: only few measurements have a significance level of 3. Although we detect a periodicity of the order of ~8.8 min in the dataset involving the measurements on all hydrogen Balmer lines with the exception of the Hα and H lines, these results have to be confirmed by additional time-resolved magnetic field observations. Fil: Hubrig, S.. European Southern Observatory Chile; Chile Fil: Briquet, M.. Katholieke Universiteit Leuven; Bélgica Fil: Morel, T.. Katholieke Universiteit Leuven; Bélgica. Université de Liège; Bélgica Fil: Schöller, M.. European Southern Observatory Chile; Chile Fil: Gonzalez, Jorge Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Complejo Astronómico "El Leoncito". Universidad Nacional de Córdoba. Complejo Astronómico "El Leoncito". Universidad Nacional de la Plata. Complejo Astronómico "El Leoncito". Universidad Nacional de San Juan. Complejo Astronómico "El Leoncito"; Argentina Fil: De Cat, P.. Koninklijke Sterrenwacht van België; Bélgica |
description |
θ Context. Carinae belongs to a group of peculiar early-type stars (OBN) with enhanced nitrogen and carbon deficiency. It is also known as a binary system, but it is not clear yet whether the chemical anomalies can be explained by mass transfer between the two components. On the basis of the previously reported spectral variability of a few metal lines it may be expected that Car possesses a weak magnetic field.Aims. A study of the physical nature of this hot massive binary which is furthermore a well-known blue straggler lying ~2 mag above the turnoff of the young open cluster IC 2602 is important to understand the origin of its strong chemical anomalies.Methods. We acquired high resolution spectroscopic and low resolution spectropolarimetric observations to achieve the following goals: a) to improve the orbital parameters to allow a more in-depth discussion on the possibility of mass transfer in the binary system; b) to carry out a non-local thermodynamic equilibrium (NLTE) abundance analysis; and c) to search for the presence of a magnetic field. Results. The study of the radial velocities using CORALIE spectra allowed us to significantly improve the orbital parameters. A comparative NLTE abundance analysis was undertaken for Car and two other early B-type stars with recently detected magnetic fields, τ Sco and ξ1 CMa. The analysis revealed significantly different abundance patterns: a one-order-of-magnitude nitrogen overabundance and carbon depletion was found in Car, while the oxygen abundance is roughly solar. For the stars ξ1 CMa and τ Sco the carbon abundance is solar and, while an N excess is also detected, it is of much smaller amplitude (0.4-0.6 dex). Such an N overabundance is typical of the values already found for other slowly-rotating (magnetic) B-type dwarfs. For Car, we attribute instead the chemical peculiarities to a past episode of mass transfer between the two binary components. The results of the search for a magnetic field using FORS 1 at the VLT consisting of 26 measurements over a time span of ~1.2 h are rather inconclusive: only few measurements have a significance level of 3. Although we detect a periodicity of the order of ~8.8 min in the dataset involving the measurements on all hydrogen Balmer lines with the exception of the Hα and H lines, these results have to be confirmed by additional time-resolved magnetic field observations. |
publishDate |
2008 |
dc.date.none.fl_str_mv |
2008-12 |
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 |
http://hdl.handle.net/11336/214862 Hubrig, S.; Briquet, M.; Morel, T.; Schöller, M.; Gonzalez, Jorge Federico; et al.; New insights into the nature of the peculiar star θ Carinae; EDP Sciences; Astronomy and Astrophysics; 488; 1; 12-2008; 287-296 0004-6361 CONICET Digital CONICET |
url |
http://hdl.handle.net/11336/214862 |
identifier_str_mv |
Hubrig, S.; Briquet, M.; Morel, T.; Schöller, M.; Gonzalez, Jorge Federico; et al.; New insights into the nature of the peculiar star θ Carinae; EDP Sciences; Astronomy and Astrophysics; 488; 1; 12-2008; 287-296 0004-6361 CONICET Digital CONICET |
dc.language.none.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
info:eu-repo/semantics/altIdentifier/doi/10.1051/0004-6361:200809972 info:eu-repo/semantics/altIdentifier/url/https://www.aanda.org/articles/aa/abs/2008/34/aa09972-08/aa09972-08.html |
dc.rights.none.fl_str_mv |
info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by-nc-sa/2.5/ar/ |
eu_rights_str_mv |
openAccess |
rights_invalid_str_mv |
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/ |
dc.format.none.fl_str_mv |
application/pdf application/octet-stream application/pdf |
dc.publisher.none.fl_str_mv |
EDP Sciences |
publisher.none.fl_str_mv |
EDP Sciences |
dc.source.none.fl_str_mv |
reponame:CONICET Digital (CONICET) instname:Consejo Nacional de Investigaciones Científicas y Técnicas |
reponame_str |
CONICET Digital (CONICET) |
collection |
CONICET Digital (CONICET) |
instname_str |
Consejo Nacional de Investigaciones Científicas y Técnicas |
repository.name.fl_str_mv |
CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicas |
repository.mail.fl_str_mv |
dasensio@conicet.gov.ar; lcarlino@conicet.gov.ar |
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1844613997830078464 |
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13.070432 |