Rotation of solar analogs cross-matching Kepler and Gaia DR2

TL;DR

This study cross-matched Kepler and Gaia DR2 data to accurately determine the rotation periods of solar analogs, revealing that some Sun-like stars continue to spin down beyond the solar age, which impacts stellar evolution understanding.

Contribution

It provides a new catalog of rotation periods for solar analogs with improved evolutionary status assessment using Gaia data, highlighting the importance of precise classification for stellar rotation studies.

Findings

Identified 10 solar analogs with rotation periods longer than the Sun's.

Confirmed rotation periods for 50 stars from previous samples.

Demonstrated the necessity of accurate evolutionary status for interpreting stellar rotation data.

Abstract

A major obstacle to interpreting the rotation period distribution for main-sequence stars from Kepler mission data has been the lack of precise evolutionary status for these objects. We address this by investigating the evolutionary status based on Gaia Data Release 2 parallaxes and photometry for more than 30,000 Kepler stars with rotation period measurements. Many of these are subgiants, and should be excluded in future work on dwarfs. We particularly investigate a 193-star sample of solar analogs, and report newly-determined rotation periods for 125 of these. These include 54 stars from a prior sample, of which can confirm the periods for 50. The remainder are new, and 10 of them longer than solar rotation period, suggesting that sun-like stars continue to spin down on the main sequence past solar age. Our sample of solar analogs could potentially serve as a benchmark for future missions such as PLATO, and emphasizes the need for additional astrometric, photometric, and spectroscopic information before interpreting the stellar populations and results from time-series surveys.