The peculiar composition of the Sun is not related to giant planets

¹ Department of Physics and Astronomy, Uppsala University, Box 516, 75120 Uppsala, Sweden
² Observatório Nacional/MCTIC, R. Gen. José Cristino, 77, 20921-400 Rio de Janeiro, Brazil
³ Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000 Aarhus C, Denmark
⁴ Department of Astronomy, Stockholm University, AlbaNova University Center, 106 91 Stockholm, Sweden

^★ Corresponding authors: mariliacarlos@on.br

Received: 25 February 2025
Accepted: 24 May 2025

Abstract

Highly differential spectroscopic studies have revealed that the Sun is deficient in refractory elements relative to solar twins. To investigate the role of giant planets on this signature, we present a high-precision abundance analysis of HARPS spectra for 50 F- and G-type stars spanning −0.4 ≲[Fe/H] ≲+0.5. There are 29 stars in the sample that host planets of masses ≳ 0.01 M_Jup.. We derived abundances for 19 elements and applied corrections to 14 of them for systematic errors associated with one dimensional (1D) model atmospheres, the assumption of local thermodynamic equilibrium (LTE), or both. We find that, among the solar twins in our sample, the Sun is Li poor in comparison to other stars at similar age, in agreement to previous studies. The sample shows a variety of trends in elemental abundances as a function of condensation temperature. We find a strong correlation in these trends with [Fe/H], with a marginally significant difference in the gradients for stars with and without giant planets detected, which increases after applying 3D and non-LTE corrections. Our overall results suggest that the peculiar composition of the Sun is primarily related to Galactic chemical evolution rather than the presence of giant planets.