The Penn State - Toru\'n Centre for Astronomy Planet Search stars. III. The evolved stars sample

TL;DR

This paper provides detailed atmospheric and physical parameters for 402 evolved stars, including many first-time measurements, and compares these with other surveys to analyze stellar and planetary characteristics.

Contribution

It offers a comprehensive set of stellar parameters for a large sample of evolved stars, including new measurements and a comparison with other planet search data, enhancing understanding of stellar and exoplanet properties.

Findings

Most stars are subgiants and giants with masses from 0.52 to 3.21 solar masses.

The sample stars are generally less metal-rich than the Sun, median [Fe/H] = -0.07.

Confirmed the increase in companion masses for evolved stars and explained the lack of close-in planets due to activity.

Abstract

We present basic atmospheric parameters ($T_{eff}$, $log g$, $v_{t}$ and [Fe/H]), rotation velocities and absolute radial velocities as well as luminosities, masses, ages and radii for 402 stars (including 11 single-lined spectroscopic binaries), mostly subgiants and giants. For 272 of them we present parameters for the first time. For another 53 stars we present estimates of $T_{eff}$ and $log g$ based on photometric calibrations. More than half objects were found to be subgiants, there is also a large group of giants and a few stars appeard to be dwarfs. The results show that the presented sample is composed of stars with masses ranging from 0.52 to $3.21 M_{\odot}$ of which 17 have masses $\geq$ $2.0 M_{\odot}$. The radii of stars studied in this paper range from 0.66 to $36.04 R_{\odot}$ with vast majority having radii between 2.0 and $4.0 R_{\odot}$. They are generally less metal abundant than the Sun with median [Fe/H]$=-0.07$. For 62 stars in common with other planet searches we found a very good agreement in obtained stellar atmospheric parameters. We also present basic properties of the complete list of 744 stars that form the PTPS evolved stars sample. We examined stellar masses for 1255 stars in five other planet searches and found some of them likely to be significantly overestimated. Applying our uniformly determined stellar masses we confirm the apparent increase of companions masses for evolved stars, and we explain it, as well as lack of close-in planets with limited effective radial velocity precision for those stars due to activity.