The chemical composition of HIP 34407/HIP 34426 and other twin-star comoving pairs

Autor(es)

Ramirez, I. ^[1] ; Khanal, S. ^{[2, 3]} ; Lichon, S. J. ^[1] ; Chaname, J. ^[4] ; Endl, M. ^{[2, 3]} ; Melendez, J. ^[5] ; Lambert, D. L. ^{[2, 3]}

Afiliação do(s) autor(es)

^[1] Tacoma Community Coll, 6501 South 19th St, Tacoma, WA 98466 - USA

^[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] Pontificia Univ Catolica Chile, Dept Astron & Astrofis, Ave Vicuna Mackenna 4860, Santiago 7820436 - Chile

^[5] Univ Sao Paulo, Dept Astron IAG USP, Rua Matao 1226, BR-05508900 Sao Paulo, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Monthly Notices of the Royal Astronomical Society; v. 490, n. 2, p. 2448-2457, DEC 2019.
• Citações Web of Science: 0

Resumo

We conducted a high-precision elemental abundance analysis of the twin-star comoving pair HIP 34407/HIP 34426. With mean error of 0.013 dex in the differential abundances (A DUI ID, a significant difference was found: HIP 34407 is more metal rich than HIP 34426. The elemental abundance differences correlate strongly with condensation temperature, with the lowest for the volatile elements like carbon around 0.05 +/- 0.02 dex, and the highest up to about 0.22 +/- 0.01 dex for the most refractory elements like aluminium. Dissimilar chemical composition for stars in twin-star comoving pairs is not uncommon, thus we compile previously published results like ours and look for correlations between abundance differences and stellar parameters, finding no significant trends with average effective temperature, surface gravity, iron abundance, or their differences. Instead, we found a weak correlation between the absolute value of abundance difference and the projected distance between the stars in each pair that appears to be more important for elements that have a low absolute abundance. If confirmed, this correlation could be an important observational constraint for binary star system formation scenarios. (AU)

• Processo FAPESP: 18/04055-8 - Espectroscopia de alta precisão: das primeiras estrelas aos planetas
• Beneficiário: Jorge Luis Melendez Moreno
• Modalidade de apoio: Auxílio à Pesquisa - Temático