Precise chemical abundances of solar twins and the signature of exoplanets

Abstract.

We obtained [X/Fe] ratios of 20 elements with high precision (0.01 - 0.02 dex) for a sample of 100 solar twins using Neural Networks (NN) and high quality spectra from HARPS. The abundances were corrected by the Galactic Chemical Evolution (GCE) and studied along with the condensation temperature (T _cond ) of the elements, to verify how distinct the Sun is compared to the solar twins. We concluded that the Sun is peculiar, being more depleted in refractories than 89% of the solar twins, with a significance of ∼9σ, which may be a signature of planetary systems like ours. The results presented here are part of Martos et al., (2025).