CD-62°1346: An extreme halo or hypervelocity CH star?

Autores
Pereira, C. B.; Jilinski, E.; Drake, N. A.; de Castro, D. B.; Ortega, V. G.; Chavero, Carolina Andrea; Roig, Fernando Virgilio
Año de publicación
2012
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
High-velocity halo stars provide important information about the properties of the extreme Galactic halo. The study of unbound and bound Population II stars permits us to better estimate the mass of the halo. Aims: We carried out a detailed spectroscopic and kinematic study and have significantly refined the distance and the evolutionary state of the star. Methods: Its atmospheric parameters, chemical abundances and kinematical properties were determined using high-resolution optical spectroscopy and employing the local-thermodynamic-equilibrium model atmospheres of Kurucz and the spectral analysis code moog. Results: We found that CD-62°1346 is a metal-poor ([Fe/H] = -1.6) evolved giant star with Teff = 5300 K and log g = 1.7. The star exhibits high carbon and s-element abundances typical of CH stars. It is also a lead star. Our kinematic analysis of its 3D space motions shows that this star has a highly eccentric (e = 0.91) retrograde orbit with an apogalactic distance of ~100 kpc, exceeding by a factor of two the distance of the Magellanic Clouds. The star travels with very high velocity relative to the Galactocentric reference frame (VGRF = 570 km s-1). Conclusions: CD-62°1346 is an evolved giant star and not a subgiant star, as was considered earlier. Whether it is bound or unbound to the Galaxy depends on the assumed mass and on the adopted Galactic potential. We also show that the star HD 5223 is another example of a high-velocity CH star that exceeds the Galactic escape velocity. Possible origins of these two high-velocity stars are briefly discussed. CD-62°1346 and HD 5223 are the first red giant stars to join the restricted group of hypervelocity stars.
Fil: Pereira, C. B.. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; Brasil
Fil: Jilinski, E.. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; Brasil. Universidade do Estado de Rio do Janeiro; Brasil. Russian Academy of Sciences. Pulkovo Observatory; Rusia
Fil: Drake, N. A.. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; Brasil. Russian Academy of Sciences. Pulkovo Observatory; Rusia
Fil: de Castro, D. B.. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; Brasil
Fil: Ortega, V. G.. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; Brasil
Fil: Chavero, Carolina Andrea. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Fil: Roig, Fernando Virgilio. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; Brasil
Materia
STARS: ABUNDANCES
STARS: CHEMICALLY PECULIAR
STARS: KINEMATICS AND DYNAMICS
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/197021
Acceder
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oai_identifier_str oai:ri.conicet.gov.ar:11336/197021
network_acronym_str CONICETDig
repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling CD-62°1346: An extreme halo or hypervelocity CH star?Pereira, C. B.Jilinski, E.Drake, N. A.de Castro, D. B.Ortega, V. G.Chavero, Carolina AndreaRoig, Fernando VirgilioSTARS: ABUNDANCESSTARS: CHEMICALLY PECULIARSTARS: KINEMATICS AND DYNAMICShttps://purl.org/becyt/ford/1.3https://purl.org/becyt/ford/1High-velocity halo stars provide important information about the properties of the extreme Galactic halo. The study of unbound and bound Population II stars permits us to better estimate the mass of the halo. Aims: We carried out a detailed spectroscopic and kinematic study and have significantly refined the distance and the evolutionary state of the star. Methods: Its atmospheric parameters, chemical abundances and kinematical properties were determined using high-resolution optical spectroscopy and employing the local-thermodynamic-equilibrium model atmospheres of Kurucz and the spectral analysis code moog. Results: We found that CD-62°1346 is a metal-poor ([Fe/H] = -1.6) evolved giant star with Teff = 5300 K and log g = 1.7. The star exhibits high carbon and s-element abundances typical of CH stars. It is also a lead star. Our kinematic analysis of its 3D space motions shows that this star has a highly eccentric (e = 0.91) retrograde orbit with an apogalactic distance of ~100 kpc, exceeding by a factor of two the distance of the Magellanic Clouds. The star travels with very high velocity relative to the Galactocentric reference frame (VGRF = 570 km s-1). Conclusions: CD-62°1346 is an evolved giant star and not a subgiant star, as was considered earlier. Whether it is bound or unbound to the Galaxy depends on the assumed mass and on the adopted Galactic potential. We also show that the star HD 5223 is another example of a high-velocity CH star that exceeds the Galactic escape velocity. Possible origins of these two high-velocity stars are briefly discussed. CD-62°1346 and HD 5223 are the first red giant stars to join the restricted group of hypervelocity stars.Fil: Pereira, C. B.. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; BrasilFil: Jilinski, E.. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; Brasil. Universidade do Estado de Rio do Janeiro; Brasil. Russian Academy of Sciences. Pulkovo Observatory; RusiaFil: Drake, N. A.. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; Brasil. Russian Academy of Sciences. Pulkovo Observatory; RusiaFil: de Castro, D. B.. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; BrasilFil: Ortega, V. G.. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; BrasilFil: Chavero, Carolina Andrea. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Roig, Fernando Virgilio. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; BrasilEDP Sciences2012-07info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/197021Pereira, C. B.; Jilinski, E.; Drake, N. A.; de Castro, D. B.; Ortega, V. G.; et al.; CD-62°1346: An extreme halo or hypervelocity CH star?; EDP Sciences; Astronomy and Astrophysics; 543; A58; 7-2012; 1-140004-63611432-0746CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/doi/10.1051/0004-6361/201219122info:eu-repo/semantics/altIdentifier/url/https://www.aanda.org/articles/aa/full_html/2012/07/aa19122-12/aa19122-12.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 Técnicas2025-10-22T11:27:47Zoai:ri.conicet.gov.ar:11336/197021instacron: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:34982025-10-22 11:27:47.239CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv CD-62°1346: An extreme halo or hypervelocity CH star?
title CD-62°1346: An extreme halo or hypervelocity CH star?
spellingShingle CD-62°1346: An extreme halo or hypervelocity CH star?
Pereira, C. B.
STARS: ABUNDANCES
STARS: CHEMICALLY PECULIAR
STARS: KINEMATICS AND DYNAMICS
title_short CD-62°1346: An extreme halo or hypervelocity CH star?
title_full CD-62°1346: An extreme halo or hypervelocity CH star?
title_fullStr CD-62°1346: An extreme halo or hypervelocity CH star?
title_full_unstemmed CD-62°1346: An extreme halo or hypervelocity CH star?
title_sort CD-62°1346: An extreme halo or hypervelocity CH star?
dc.creator.none.fl_str_mv Pereira, C. B.
Jilinski, E.
Drake, N. A.
de Castro, D. B.
Ortega, V. G.
Chavero, Carolina Andrea
Roig, Fernando Virgilio
author Pereira, C. B.
author_facet Pereira, C. B.
Jilinski, E.
Drake, N. A.
de Castro, D. B.
Ortega, V. G.
Chavero, Carolina Andrea
Roig, Fernando Virgilio
author_role author
author2 Jilinski, E.
Drake, N. A.
de Castro, D. B.
Ortega, V. G.
Chavero, Carolina Andrea
Roig, Fernando Virgilio
author2_role author
author
author
author
author
author
dc.subject.none.fl_str_mv STARS: ABUNDANCES
STARS: CHEMICALLY PECULIAR
STARS: KINEMATICS AND DYNAMICS
topic STARS: ABUNDANCES
STARS: CHEMICALLY PECULIAR
STARS: KINEMATICS AND DYNAMICS
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.3
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv High-velocity halo stars provide important information about the properties of the extreme Galactic halo. The study of unbound and bound Population II stars permits us to better estimate the mass of the halo. Aims: We carried out a detailed spectroscopic and kinematic study and have significantly refined the distance and the evolutionary state of the star. Methods: Its atmospheric parameters, chemical abundances and kinematical properties were determined using high-resolution optical spectroscopy and employing the local-thermodynamic-equilibrium model atmospheres of Kurucz and the spectral analysis code moog. Results: We found that CD-62°1346 is a metal-poor ([Fe/H] = -1.6) evolved giant star with Teff = 5300 K and log g = 1.7. The star exhibits high carbon and s-element abundances typical of CH stars. It is also a lead star. Our kinematic analysis of its 3D space motions shows that this star has a highly eccentric (e = 0.91) retrograde orbit with an apogalactic distance of ~100 kpc, exceeding by a factor of two the distance of the Magellanic Clouds. The star travels with very high velocity relative to the Galactocentric reference frame (VGRF = 570 km s-1). Conclusions: CD-62°1346 is an evolved giant star and not a subgiant star, as was considered earlier. Whether it is bound or unbound to the Galaxy depends on the assumed mass and on the adopted Galactic potential. We also show that the star HD 5223 is another example of a high-velocity CH star that exceeds the Galactic escape velocity. Possible origins of these two high-velocity stars are briefly discussed. CD-62°1346 and HD 5223 are the first red giant stars to join the restricted group of hypervelocity stars.
Fil: Pereira, C. B.. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; Brasil
Fil: Jilinski, E.. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; Brasil. Universidade do Estado de Rio do Janeiro; Brasil. Russian Academy of Sciences. Pulkovo Observatory; Rusia
Fil: Drake, N. A.. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; Brasil. Russian Academy of Sciences. Pulkovo Observatory; Rusia
Fil: de Castro, D. B.. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; Brasil
Fil: Ortega, V. G.. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; Brasil
Fil: Chavero, Carolina Andrea. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Fil: Roig, Fernando Virgilio. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; Brasil
description High-velocity halo stars provide important information about the properties of the extreme Galactic halo. The study of unbound and bound Population II stars permits us to better estimate the mass of the halo. Aims: We carried out a detailed spectroscopic and kinematic study and have significantly refined the distance and the evolutionary state of the star. Methods: Its atmospheric parameters, chemical abundances and kinematical properties were determined using high-resolution optical spectroscopy and employing the local-thermodynamic-equilibrium model atmospheres of Kurucz and the spectral analysis code moog. Results: We found that CD-62°1346 is a metal-poor ([Fe/H] = -1.6) evolved giant star with Teff = 5300 K and log g = 1.7. The star exhibits high carbon and s-element abundances typical of CH stars. It is also a lead star. Our kinematic analysis of its 3D space motions shows that this star has a highly eccentric (e = 0.91) retrograde orbit with an apogalactic distance of ~100 kpc, exceeding by a factor of two the distance of the Magellanic Clouds. The star travels with very high velocity relative to the Galactocentric reference frame (VGRF = 570 km s-1). Conclusions: CD-62°1346 is an evolved giant star and not a subgiant star, as was considered earlier. Whether it is bound or unbound to the Galaxy depends on the assumed mass and on the adopted Galactic potential. We also show that the star HD 5223 is another example of a high-velocity CH star that exceeds the Galactic escape velocity. Possible origins of these two high-velocity stars are briefly discussed. CD-62°1346 and HD 5223 are the first red giant stars to join the restricted group of hypervelocity stars.
publishDate 2012
dc.date.none.fl_str_mv 2012-07
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/11336/197021
Pereira, C. B.; Jilinski, E.; Drake, N. A.; de Castro, D. B.; Ortega, V. G.; et al.; CD-62°1346: An extreme halo or hypervelocity CH star?; EDP Sciences; Astronomy and Astrophysics; 543; A58; 7-2012; 1-14
0004-6361
1432-0746
CONICET Digital
CONICET
url http://hdl.handle.net/11336/197021
identifier_str_mv Pereira, C. B.; Jilinski, E.; Drake, N. A.; de Castro, D. B.; Ortega, V. G.; et al.; CD-62°1346: An extreme halo or hypervelocity CH star?; EDP Sciences; Astronomy and Astrophysics; 543; A58; 7-2012; 1-14
0004-6361
1432-0746
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/doi/10.1051/0004-6361/201219122
info:eu-repo/semantics/altIdentifier/url/https://www.aanda.org/articles/aa/full_html/2012/07/aa19122-12/aa19122-12.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/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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score 12.982451

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