Stars with and without planets: Where do they come from?

TL;DR

This study investigates the chemical abundance patterns of 148 solar-like stars, revealing correlations with stellar age and galactic origin, and clarifying the chemical signatures associated with planet-hosting stars.

Contribution

It identifies key correlations between chemical abundance trends and stellar parameters, highlighting the influence of age and galactic birthplace on stellar chemical signatures.

Findings

Tc slope correlates with stellar age and surface gravity.

Stars from inner Galaxy show fewer refractory elements.

Chemical peculiarities of planet-hosting stars are linked to age and origin.

Abstract

A long and thorough investigation of chemical abundances of planet-hosting stars that lasted for more than a decade has finally beared fruit. We explore a sample of 148 solar-like stars to search for a possible correlation between the slopes of the abundance trends versus condensation temperature (known as the Tc slope) both with stellar parameters and Galactic orbital parameters in order to understand the nature of the peculiar chemical signatures of these stars and the possible connection with planet formation. We find that the Tc slope correlates at a significant level (at more than 4sigma) with the stellar age and the stellar surface gravity. We also find tentative evidence that the Tc slope correlates with the mean galactocentric distance of the stars (Rmean), suggesting that stars that originated in the inner Galaxy have fewer refractory elements relative to the volatile ones. We found that the chemical peculiarities (small refractory-to-volatile ratio) of planet-hosting stars is merely a reflection of their older age and their inner Galaxy origin. We conclude that the stellar age and probably Galactic birth place are key to establish the abundances of some specific elements.