Planets Around Solar Twins/Analogs (PASTA). I. High-precision Stellar Chemical Abundances for 17 Planet-hosting Stars and the Condensation Temperature Trend

Abstract

The Sun is depleted in refractory elements compared to nearby solar twins, which may be linked to the formation of giant or terrestrial planets. Here we present high-resolution, high signal-to-noise spectroscopic data for 17 solar-like stars hosting planets, obtained with Magellan II/MIKE, to investigate whether this depletion is related to planet formation. We derive stellar parameters, including stellar atmosphere, age, radius, mass, and chemical abundances for 22 elements from carbon to europium through line-by-line differential analysis. Our uncertainties range from 0.01 dex for Fe and Si to 0.08 dex for Sr, Y, and Eu. By comparing the solar abundances to those of the 17 stars, we investigate the differential abundance ([X/Fe]solar-[X/Fe]star) versus condensation temperature (Tc) trend. In particular, we apply Galactic chemical evolution corrections to five solar twins within the full sample. Our results conform to previous studies that the Sun is relatively depleted in refractory compared to volatile elements. For both five solar twins and the rest of the solar-like stars, we find that all stars hosting known gas giant planets exhibit negative Tc trend slopes, suggesting that the Sun is relatively depleted in refractory elements compared to similar giant planet-hosting stars. Additionally, we find no correlation between Tc trend slopes and the total mass of detected terrestrial planets in each system, suggesting that terrestrial planet formation may not be the cause of refractory element depletion in the Sun. Show more