RESEARCH
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Chemical composition of stars with massive planets

T. Mishenina, N. Basak, V. Zh. Adibekyan, C. Soubiran, V. Kovtyukh

Abstract
Stellar parameters of 25 planet-hosting stars and abundances of Li, C, O, Na, Mg, Al, S, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Ni, Zn, Y, Zr, Ba, Ce, Pr, Nd, Sm, and Eu were studied based on homogeneous high-resolution spectra and uniform techniques. The iron abundance [Fe/H] and key elements (Li, C, O, Mg, Si) indicative of the planet formation, as well as the dependences of [El/Fe] on Tcond, were analysed. The iron abundances determined in our sample stars with detected massive planets range within –0.3 < [Fe/H] < 0.4. The behaviour of [C/Fe], [O/Fe], [Mg/Fe], and [Si/Fe] relative to [Fe/H] is consistent with the Galactic Chemical Evolution trends. The mean values of C/O and [C/O] are ⟨C/O⟩ = 0.48 ± 0.07 and ⟨[C/O]⟩ = –0.07 ± 0.07, which are slightly lower than solar ones. The Mg/Si ratios range from 0.83 to 0.95 for four stars in our sample and from 1.0 to 1.86 for the remaining 21 stars. Various slopes of [El/Fe] versus Tcond were found. The dependences of the planetary mass on metallicity, the lithium abundance, the C/O and Mg/Si ratios, and also on the [El/Fe]–Tcond slopes were considered.

Keywords
stars: abundances; stars: late-type; planetary systems; Astrophysics - Solar and Stellar Astrophysics; Astrophysics - Earth and Planetary Astrophysics

Monthly Notices of the Royal Astronomical Society
Volume 504, Issue 3, Page 4252
2021 July

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Faculdade de Ciências da Universidade de Lisboa Universidade do Porto Faculdade de Ciências e Tecnologia da Universidade de Coimbra
Fundação para a Ciência e a Tecnologia COMPETE 2020 PORTUGAL 2020 União Europeia