Constraining differential rotation of Sun-like stars from asteroseismic and starspot rotation periods

TL;DR

This study compares asteroseismic and starspot rotation periods of Sun-like stars, finding consistent results indicating weak radial differential rotation and highlighting challenges in stellar age estimation.

Contribution

It demonstrates the agreement between asteroseismic and starspot rotation measurements for Sun-like stars and discusses implications for differential rotation and age estimation.

Findings

Rotation periods from both methods agree within uncertainties.

Radial differential rotation appears to be weak, similar to the Sun.

Asteroseismic and gyrochronology ages show significant discrepancies.

Abstract

In previous work we identified six Sun-like stars observed by Kepler with exceptionally clear asteroseismic signatures of rotation. Here, we show that five of these stars exhibit surface variability suitable for measuring rotation. In order to further constrain differential rotation, we compare the rotation periods obtained from light-curve variability with those from asteroseismology. The two rotation measurement methods are found to agree within uncertainties, suggesting that radial differential rotation is weak, as is the case for the Sun. Furthermore, we find significant discrepancies between ages from asteroseismology and from three different gyrochronology relations, implying that stellar age estimation is problematic even for Sun-like stars.