Volatiles and refratories in solar analogs: no terrestial planet connection

TL;DR

This study analyzed high-quality spectra of 95 solar analogs to investigate if chemical abundance patterns correlate with terrestrial planet presence, finding no significant differences after accounting for galactic chemical evolution.

Contribution

It provides evidence that chemical abundance ratios in solar analogs are not indicative of terrestrial planet presence, challenging previous assumptions.

Findings

Stars with and without planets show similar abundance ratios.

Two systems with super-Earths differ from expected abundance patterns.

Galactic chemical evolution effects account for observed abundance differences.

Abstract

We have analysed very high-quality HARPS and UVES spectra of 95 solar analogs, 24 hosting planets and 71 without detected planets, to search for any possible signature of terrestial planets in the chemical abundances of volatile and refractory elements with respect to the solar abundances. We demonstrate that stars with and without planets in this sample show similar mean abundance ratios, in particular, a sub-sample of 14 planet-host and 14 "single" solar analogs in the metallicity range 0.14<[Fe/H]<0.36. In addition, two of the planetary systems in this sub-sample, containing each of them a super-Earth-like planet with masses in the range ~ 7-11 Earth masses, have different volatile-to-refratory abundance ratios to what would be expected from the presence of a terrestial planets. Finally, we check that after removing the Galactic chemical evolution effects any possible difference in mean abundances, with respect to solar values, of refratory and volatile elements practically dissappears.