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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Correlation between lithium abundances and ages of solar twin stars

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Autor(es):
Carlos, Marilia [1] ; Nissen, Poul E. [2] ; Melendez, Jorge [1]
Número total de Autores: 3
Afiliação do(s) autor(es):
[1] Univ Sao Paulo, Dept Astron, IAG, Rua Matao 1226, Cidade Univ, BR-05508900 Sao Paulo, SP - Brazil
[2] Aarhus Univ, Stellar Astrophys Ctr, Dept Phys & Astron, Ny Munkegade 120, DK-8000 Aarhus C - Denmark
Número total de Afiliações: 2
Tipo de documento: Artigo Científico
Fonte: Astronomy & Astrophysics; v. 587, MAR 2016.
Citações Web of Science: 24
Resumo

Aims. We want to determine the lithium abundances of solar twin stars as a function of stellar age to provide constraints for stellar evolutions models and to investigate whether there is a connection between low Li abundance and the occurrence of planets. Methods. For a sample of 21 solar twins observed with the HARPS spectrograph at high spectral resolution (R similar or equal to 115.000) and very high signal-to-noise ratio (600 <= S/N <= 2400), precise lithium abundances were obtained by spectral synthesis of the Li I 6707.8 angstrom line and compared to stellar ages, masses, and metallicities determined from a spectroscopic analysis of the same set of HARPS spectra. Results. We show that for the large majority of the solar twins there is a strong correlation between lithium abundance and stellar age. As the age increases from 1 to 9Gyr, the Li abundance decreases by a factor of similar to 50. The relation agrees fairly well with predictions from non-standard stellar evolution models of Li destruction at the bottom of the upper convection zone. Two stars deviate from the relation by having Li abundances enhanced by a factor of similar to 10, which may be due to planet engulfment. On the other hand, we find no indication of a link between planet hosting stars and enhanced lithium depletion. (AU)

Processo FAPESP: 12/24392-2 - Espectroscopia de alta precisão: impacto no estudo de planetas, estrelas, a galáxia e cosmologia
Beneficiário:Jorge Luis Melendez Moreno
Linha de fomento: Auxílio à Pesquisa - Temático