Chemical abundances in 849 exoplanet hosts stars

We find the planet mass-abundance correlation to be primarily negative for {alpha}-elements and marginally positive or zero for the iron-peak elements, indicating that stars hosting giant planets are relatively younger. This is further validated by the age of the host stars obtained from isochrone fitting. The later enrichment of protoplanetary material with iron and iron-peak elements is also consistent with the formation of the giant planets via the core accretion process.

A higher metal fraction in the protoplanetary disk is conducive to rapid core growth, thus providing a plausible route for the formation of giant planets. This study, therefore, indicates that the observed trends in stellar abundances and planet mass are most likely a natural consequence of Galactic chemical evolution.