  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.

Solar and Stellar Astrophysics;Earth and Planetary Astrophysics