Show simple item record

dc.contributor.author Groh, J. H.
dc.contributor.author Damineli, A.
dc.contributor.author Hillier, D. J.
dc.contributor.author Barba, Rodolfo Hector
dc.contributor.author Fernandez Lajus, Eduardo Eusebio
dc.contributor.author Gamen, Roberto Claudio
dc.contributor.author Moisés, A. P.
dc.contributor.author Solivella, Gladys Rebeca
dc.contributor.author Teodoro, M.
dc.date.available 2018-04-23T14:11:46Z
dc.date.issued 2009-12
dc.identifier.citation Groh, J. H.; Damineli, A.; Hillier, D. J.; Barba, Rodolfo Hector; Fernandez Lajus, Eduardo Eusebio; et al.; Bona-fide, strong-variable galactic Luminous Blue Variable stars are fast rotators: detection of a high rotational velocity in HR Carinae; IOP Publishing; Astrophysical Journal; 705; 12-2009; 25-30
dc.identifier.issn 0004-637X
dc.identifier.uri http://hdl.handle.net/11336/42988
dc.description.abstract We report optical observations of the Luminous Blue Variable (LBV) HR Carinae which show that the star has reached a visual minimum phase in 2009. More importantly, we detected absorptions due to Si IV 4088-4116 Angstroms. To match their observed line profiles from 2009 May, a high rotational velocity of vrot=150 +- 20 km/s is needed (assuming an inclination angle of 30 degrees), implying that HR Car rotates at ~0.88 +- 0.2 of its critical velocity for break-up (vcrit). Our results suggest that fast rotation is typical in all strong-variable, bona-fide galactic LBVs, which present S Dor-type variability. Strong-variable LBVs are located in a well-defined region of the HR diagram during visual minimum (the "LBV minimum instability strip"). We suggest this region corresponds to where vcrit is reached. To the left of this strip, a forbidden zone with vrot/vcrit>1 is present, explaining why no LBVs are detected in this zone. Since dormant/ex LBVs like P Cygni and HD 168625 have low vrot, we propose that LBVs can be separated in two groups: fast-rotating, strong-variable stars showing S-Dor cycles (such as AG Car and HR Car) and slow-rotating stars with much less variability (such as P Cygni and HD 168625). We speculate that SN progenitors which had S-Dor cycles before exploding (such as in SN 2001ig, SN 2003bg, and SN 2005gj) could have been fast rotators. We suggest that the potential difficulty of fast-rotating Galactic LBVs to lose angular momentum is an additional evidence that such stars could explode during the LBV phase.
dc.format application/pdf
dc.language.iso eng
dc.publisher IOP Publishing
dc.rights info:eu-repo/semantics/openAccess
dc.rights.uri https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
dc.subject Stars
dc.subject Atmospheres
dc.subject HR Carinae
dc.subject Mass loss
dc.subject Rotation
dc.subject Variable stars
dc.subject Supergiant stars
dc.subject.classification Astronomía
dc.subject.classification Ciencias Físicas
dc.subject.classification CIENCIAS NATURALES Y EXACTAS
dc.title Bona-fide, strong-variable galactic Luminous Blue Variable stars are fast rotators: detection of a high rotational velocity in HR Carinae
dc.type info:eu-repo/semantics/article
dc.type info:ar-repo/semantics/artículo
dc.type info:eu-repo/semantics/publishedVersion
dc.date.updated 2018-04-19T18:32:16Z
dc.journal.volume 705
dc.journal.pagination 25-30
dc.journal.pais Estados Unidos
dc.description.fil Fil: Groh, J. H.. Max-Planck-Institut fur Radioastronomie; Alemania
dc.description.fil Fil: Damineli, A.. Universidade de Sao Paulo; Brasil
dc.description.fil Fil: Hillier, D. J.. Universidade de Sao Paulo; Brasil
dc.description.fil Fil: Barba, Rodolfo Hector. Universidad de La Serena; Chile. 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
dc.description.fil Fil: Fernandez Lajus, Eduardo Eusebio. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; Argentina
dc.description.fil Fil: Gamen, Roberto Claudio. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; Argentina
dc.description.fil Fil: Moisés, A. P.. Universidade de Sao Paulo; Brasil
dc.description.fil Fil: Solivella, Gladys Rebeca. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; Argentina
dc.description.fil Fil: Teodoro, M.. Universidade de Sao Paulo; Brasil
dc.journal.title Astrophysical Journal
dc.relation.alternativeid info:eu-repo/semantics/altIdentifier/doi/http://dx.doi.org/10.1088/0004-637X/705/1/L25
dc.conicet.fuente unificacion


Archivos asociados

This item appears in the following Collection(s)

Show simple item record

info:eu-repo/semantics/openAccess Excepto donde se diga explícitamente, este item se publica bajo la siguiente descripción: Creative Commons Attribution-NonCommercial-ShareAlike 2.5 Unported (CC BY-NC-SA 2.5)