The impact of stellar metallicity on rotation and activity evolution in the Kepler field using gyro-kinematic ages

TL;DR

This study investigates how stellar metallicity influences the rotation and magnetic activity evolution of low-mass stars in the Kepler field, using gyro-kinematic ages and photometric activity indices, confirming some theoretical predictions.

Contribution

It provides observational evidence linking metallicity to stellar rotation rates at late ages, advancing understanding of stellar magnetic activity evolution.

Findings

Metal-rich stars spin down to slower rotation at late ages.

Evidence supports metallicity-dependent stellar rotation evolution.

Further research needed on activity evolution dependence.

Abstract

In recent years, there has been a push to understand how chemical composition affects the magnetic activity levels of main sequence low-mass stars. Results indicate that more metal-rich stars are more magnetically active for a given stellar mass and rotation period. This metallicity dependence has implications for how the rotation periods and activity levels of low-mass stars evolve over their lifetimes. Numerical modelling suggests that at late ages more metal-rich stars should be rotating more slowly and be more magnetically active. In this work, we study the rotation and activity evolution of low-mass stars using a sample of Kepler field stars. We use the gyro-kinematic age dating technique to estimate ages for our sample and use the photometric activity index as our proxy for magnetic activity. We find clear evidence that, at late ages, more metal-rich stars have spun down to slower rotation in agreement with the theoretical modeling. However, further investigation is required to definitively determine whether the magnetic activity evolution occurs in a metallicity dependent way.