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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.)

High-precision analysis of the solar twin HIP 100963

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Autor(es):
Galarza, Jhon Yana [1] ; Melendez, Jorge [1] ; Ramirez, Ivan [2, 3] ; Yong, David [4] ; Karakas, Amanda I. [4] ; Asplund, Martin [4] ; Liu, Fan [4]
Número total de Autores: 7
Afiliação do(s) autor(es):
[1] Univ Sao Paulo, IAG, Dept Astron, Rua Matao 1226, BR-05509900 Sao Paulo, SP - Brazil
[2] Univ Texas Austin, McDonald Observ, 2515 Speedway, Austin, TX 78712 - USA
[3] Univ Texas Austin, Dept Astron, 2515 Speedway, Austin, TX 78712 - USA
[4] Australian Natl Univ, Res Sch Astron & Astrophys, Mt Stromlo Observ, Via Cotter Rd, Weston, ACT 2611 - Australia
Número total de Afiliações: 4
Tipo de documento: Artigo Científico
Fonte: Astronomy & Astrophysics; v. 589, MAY 2016.
Citações Web of Science: 9
Resumo

Context. HIP 100963 was one of the first solar twins identified. Although some high-precision analyses are available, a comprehensive high-precision study of chemical elements from different nucleosynthetic sources is still lacking from which to obtain potential new insights on planets, stellar evolution, and Galactic chemical evolution (GCE). Aims. We analyze and investigate the origin of the abundance pattern of HIP 100963 in detail, in particular the pattern of the light element Li, the volatile and refractory elements, and heavy elements from the s- and r-processes. Methods. We used the HIRES spectrograph on the Keck I telescope to acquire high-resolution (R approximate to 70 000) spectra with a high signal-to-noise ratio (S/N approximate to 400-650 per pixel) of HIP 100963 and the Sun for a differential abundance analysis. We measured the equivalent widths (EWs) of iron lines to determine the stellar parameters by employing the differential spectroscopic equilibrium. We determined the composition of volatile, refractory, and neutron-capture elements through a differential abundance analysis with respect to the Sun. Results. The stellar parameters we found are T-eff = 5818 +/- 4 K, log g = 4.49 +/- 0.01 dex, nu(t) = 1.03 +/- 0.01 km s(-1), and {[}Fe/H] = -0.003 +/- 0.004 dex. These low errors allow us to compute a precise mass (1.03(-0.01)(+0.02) M-circle dot) and age (2.0 +/- 0.4 Gyr), obtained using Yonsei-Yale isochrones. Using our {[}Y/Mg] ratio, we have determined an age of 2.1 +/- 0.4 Gyr, in agreement with the age computed using isochrones. Our isochronal age also agrees with the age determined from stellar activity (2.4 +/- 0.3 Gyr). We study the abundance pattern with condensation temperature (T-cond) taking corrections by the GCE into account. We show that the enhancements of neutron-capture elements are explained by contributions from both the s- and r-process. The lithium abundance follows the tight Li-age correlation seen in other solar twins. Conclusions. We confirm that HIP 100963 is a solar twin and demonstrate that its abundance pattern is about solar after corrections for GCE. The star also shows enrichment in s-and r-process elements, as well as depletion in lithium that is caused by stellar evolution. (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