Please use this identifier to cite or link to this item: http://hdl.handle.net/2248/3199
Full metadata record
DC FieldValueLanguage
dc.contributor.authorJasniewicz, G-
dc.contributor.authorParthasarathy, M-
dc.contributor.authorde Laverny, P-
dc.contributor.authorThévenin, F-
dc.date.accessioned2008-08-19T05:22:55Z-
dc.date.available2008-08-19T05:22:55Z-
dc.date.issued1999-02-
dc.identifier.citationAstronomy and Astrophysics, Vol. 342, No. 3, pp. 831 - 838en
dc.identifier.issn0004 - 6361-
dc.identifier.urihttp://hdl.handle.net/2248/3199-
dc.description.abstractde la Reza et al. (1997) suggested that all K giants become Li-rich for a short time. During this period the giants are associated with an expanding thin circumstellar shell supposedly triggered by an abrupt internal mixing mechanism resulting in the surface Li enrichment. In order to test this hypothesis twenty nine late-type giants with far-infrared excess from the list of Zuckerman et al. (1995) were observed in the Li-region to study the connection between the circumstellar shells and Li abundance. Eight giants have been found to have log epsilon (Li) > 1.0. In the remaining giants the Li abundance is found to be much lower. HD 219025 is found to be a rapidly rotating (projected rotational velocity of 23 +/-3 km s(-1) ), dusty and Li-rich (log epsilon (Li) = 3.0+/-0.2) K giant. Absolute magnitude derived from the Hipparcos parallax reveals that it is a giant and not a pre-main-sequence star. The evolutionary status of HD 219025 seems to be similar to that of HDE 233517 which is also a rapidly rotating, dusty and Li-rich K giant. The Hipparcos parallaxes of all the well studied Li-rich K giants show that most of them are brighter than the ``clump" giants. Their position in the H-R diagram indicates that they have gone through mixing and the initial abundance of Li is not preserved. There seems to be no correlations between Li abundances, rotational velocities and carbon isotope ratios. The only satisfactory explanation for the overabundance of lithium in these giants is the creation of Li by the extra deep mixing and the associated ``cool bottom processing". Based on observations obtained at the European Southern Observatory, La Silla, Chile, and at the Observatoire de Haute Provence, France.en
dc.format.extent363480 bytes-
dc.format.mimetypeapplication/pdf-
dc.language.isoenen
dc.publisherEuropean Southern Observatoryen
dc.relation.urihttp://adsabs.harvard.edu/abs/1999A%26A...342..831Jen
dc.subjectStars:Abundancesen
dc.subjectStars:Circumstellar Matteren
dc.subjectStars:Evolutionen
dc.subjectStars:individual HD 219025en
dc.titleLate-type giants with infrared excess. I. Lithium abundancesen
dc.typeArticleen
Appears in Collections:IIAP Publications

Files in This Item:
File Description SizeFormat 
Late-type giants with infrared excess354.96 kBAdobe PDFThumbnail
View/Open


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.