| Full text | |
| Author(s): |
Total Authors: 3
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| Affiliation: | [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
Total Affiliations: 2
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| Document type: | Journal article |
| Source: | Astronomy & Astrophysics; v. 587, MAR 2016. |
| Web of Science Citations: | 26 |
| Abstract | |
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) | |
| FAPESP's process: | 12/24392-2 - High precision spectroscopy: impact in the study of planets, stars, the galaxy and cosmology |
| Grantee: | Jorge Luis Melendez Moreno |
| Support Opportunities: | Research Projects - Thematic Grants |