Supersolar metallicity in G0–G3 main-sequence stars with V < 15. II. An extension of the sample

Abstract

ABSTRACT We present the spectroscopic analysis at intermediate resolution of a new sample of 146 Sun-like stars (of spectral types G0–G3 and luminosity class V), which complements the data set of 233 targets previously investigated. Aimed at identifying objects with supersolar metallicity, we conducted observations at the Observatorio Astrofísico Guillermo Haro and derived the basic stellar atmospheric parameters, namely the effective temperature, surface gravity, and global metallicity, based on a set of absorption spectroscopic indices in the wavelength region 3800–4800 Å. The newly derived set of parameters is in good agreement with previous determinations collected from sources in the literature. Considering the full sample of our investigation (379 stars), we also compared the effective temperatures of stars in common (354 objects) with Gaia DR2 for which temperatures are available, and found that, on average, our values are about 100 K higher. We show that most of the largest temperature discrepancies can plausibly be ascribed to interstellar extinction effects on Gaia’s photometry. Finally, within the working sample we found four more stars that present supermetallicity, one of which was previously reported in the literature.