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Is ξ Boo AB a Young or an Evolved System? A Model Atmosphere Analysis

Published online by Cambridge University Press:  12 April 2016

I.S. Savanov*
Affiliation:
Crimean Astrophysical Observatory, Nauchny, 334413 Crimea, USSR

Abstract

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We perform a model atmosphere analysis of ξ Boo A, and make estimates for the secondary component. The abundances of 25 elements for ξ Boo A are obtained with the parameters: Teff=(5300 ± 100) K, log g= 4.1 ± 0.2, ξt = 0.5km/s. The atmosphere of ξ Boo A is deficient in Y and Zr, but overabundant in Ba and rare earth elements. We confirm the high Li abundance in ξBoo A (logA(Li) = 2.1), while Li is strongly underabundant in the secondary relative to the Sun. From comparison with evolutionary calculations we find that ξ Boo A has mass 0.95 M, radius 1.4 R we also determine a rotational velocity v sin i = 8 km/s. We conclude that, in spite of its relatively high rotation rate and high chromospheric activity, it is already evolved from the main-sequence.

Type
Part IV Stellar activity
Copyright
Copyright © Springer-Verlag 1991

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