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

Adibekyan, V. Zh.; Gonzalez Hernandez, J. I.; Delgado Mena, E.; Sousa, S. G.; Santos, N. C.; Israelian, G.; Figueira, P.; Bertran de Lis, S.
Bibliographical reference

18th Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, Proceedings of the conference held at Lowell Observatory, 8-14 June, 2014. Edited by G. van Belle and H.C. Harris., pp.789-795

Advertised on:
1
2015
Number of authors
8
IAC number of authors
3
Citations
1
Refereed citations
1
Description
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 T_{c} 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 T_{c} slope correlates at a significant level (at more than 4σ) with the stellar age and the stellar surface gravity. We also find tentative evidence that the T_{c} slope correlates with the mean galactocentric distance of the stars (R_{mean}), 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.