Lithium and magnetic fields in giant stars: HD 232 862: a magnetic and lithium-rich giant

Lèbre, A.; Palacios, A.; Nascimento Jr., J. D. do; Konstantinova-Antova, R.; Kolev, D.; Aurière, M.; Laverny, P. de; Medeiros, José Renan de

Lithium and magnetic fields in giant stars: HD 232 862: a magnetic and lithium-rich giant

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dc.contributor.author	Lèbre, A.
dc.contributor.author	Palacios, A.
dc.contributor.author	Nascimento Jr., J. D. do
dc.contributor.author	Konstantinova-Antova, R.
dc.contributor.author	Kolev, D.
dc.contributor.author	Aurière, M.
dc.contributor.author	Laverny, P. de
dc.contributor.author	Medeiros, José Renan de
dc.date.accessioned	2020-05-18T18:07:31Z
dc.date.available	2020-05-18T18:07:31Z
dc.date.issued	2009-07-22
dc.description.resumo	Aims. We report the detection of an unusually high lithium content in HD 232 862, a field giant classified as a G8II star, and hostinga magnetic field. Methods. With the spectropolarimeters ESPaDOnS at CFHT and NARVAL at TBL, we collected high resolution and high signalto-noise spectra of three giants: HD 232 862, KU Peg and HD 21 018. From spectral synthesis we inferred stellar parameters and measured lithium abundances that we compared to predictions from evolutionary models. We also analysed Stokes V signatures, looking for a magnetic field on these giants. Results. HD 232 862, presents a very high abundance of lithium (ALi = 2.45 ± 0.25 dex), far in excess of the theoretically value expected at this spectral type and for this luminosity class (i.e., G8II). The evolutionary stage of HD 232 862 was determined, and it suggests a mass in the lower part of the [1.0 M, 3.5 M] mass interval, likely 1.5–2.0 M, at the bottom of the red giant branch. Also, a time variable Stokes V signature was detected in the data of HD 232 862 and KU Peg, pointing to the presence of a magnetic field at the surface of these two rapidly rotating active stars.	pt_BR
dc.identifier.citation	MEDEIROS, José Renan de et al. Lithium and magnetic fields in giant stars. Astronomy & Astrophysics (Berlin. Print), v. 504, p. 1011-1019, 2009. ISSN 1432-0746 versão online. DOI https://doi.org/10.1051/0004-6361/200912038. Disponível: https://www.aanda.org/articles/aa/abs/2009/36/aa12038-09/aa12038-09.html. Acesso em: 18 maio 2020. Reproduzido com permissão da Astronomy & Astrophysics, © ESO.	pt_BR
dc.identifier.doi	10.1051/0004-6361/200912038
dc.identifier.issn	0004-6361 (print), 1432-0746 (online)
dc.identifier.uri	https://repositorio.ufrn.br/jspui/handle/123456789/28994
dc.language	en	pt_BR
dc.publisher	Astronomy & Astrophysics	pt_BR
dc.subject	Stars: abundances	pt_BR
dc.subject	Stars: evolution	pt_BR
dc.subject	Stars: magnetic fields	pt_BR
dc.subject	Stars: individual: HD 232 862	pt_BR
dc.subject	Stars: individual: KU Peg	pt_BR
dc.title	Lithium and magnetic fields in giant stars: HD 232 862: a magnetic and lithium-rich giant	pt_BR
dc.type	article	pt_BR