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New Candidates for Chromospherically Young, Kinematically Old Stars

Published online by Cambridge University Press:  24 September 2020

Eduardo Machado Pereira Open the ORCID record for Eduardo Machado Pereira [Opens in a new window]  and
Helio J. Rocha Pinto
Eduardo Machado Pereira
Affiliation:
Observatório do Valongo, Universidade Federal do Rio de Janeiro, Ladeira do Pedro Antônio, 43, - Centro, 20080-090, Rio de Janeiro - RJ, Brazil email: eduardo11@astro.ufrj.br
Helio J. Rocha Pinto
Affiliation:
Observatório do Valongo, Universidade Federal do Rio de Janeiro, Ladeira do Pedro Antônio, 43, - Centro, 20080-090, Rio de Janeiro - RJ, Brazil email: eduardo11@astro.ufrj.br
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Abstract

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Roughly speaking, young stars are associated to intense chromospheric activity (CA), whereas it decreases with stellar aging. However, some objects that show high kinematical components – in turn, associated to older stars – reveal CA similar to that of young ones; we call these stars chromospherically young and kinematically old (CYKOs). One hypothesis that could explain their occurrence is the merge of a short-period binary, from which the outcome would be a chromospherically active, kinematically evolved star. Considering that they evolved separately, we expect them to be lithium depleted, and therefore we look for CYKO stars by analyzing their lithium content (λ 6707 Å). We present a preliminary list of 48 stars matching this criteria, aiming to either confirm or discard the coalescence of a short-period pair hypothesis.

Keywords

late type starsstars: chromospheric activityspace velocitiesstars: spectroscopy
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 15 , Symposium S354: Solar and Stellar Magnetic Fields: Origins and Manifestations , June 2019 , pp. 211 - 214
Copyright
© International Astronomical Union 2020

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