The rotation-activity relation of M dwarfs: From K2 to TESS and PLATO

TL;DR

This study investigates the rotation-activity relationship in M dwarfs using K2 data, confirming a significant activity change at a 10-day rotation period with a larger sample for stronger statistical evidence.

Contribution

It provides the first comprehensive analysis of M dwarf rotation-activity relation using K2 data, significantly expanding the sample size and confirming the activity transition at ~10 days.

Findings

Confirmed the abrupt change in activity at ~10 days rotation period.

Analyzed 430 M dwarfs from K2 data.

Enhanced statistical significance of the rotation-activity relation.

Abstract

Studies of the rotation-activity relation of late-type stars are essential to enhance our understanding of stellar dynamos and angular momentum evolution. We study the rotation-activity relation with K2 for M dwarfs where it is especially poorly understood. We analyzed the light curves of all bright and nearby M dwarfs form the Superblink proper motion catalog that were in the K2 field of view. For a sample of 430 M dwarfs observed in campaigns C0-C19 in long cadence mode we determined the rotation period and a wealth of activity diagnostics. Our study of the rotation-activity relation based on photometric activity indicators confirmed the previously published abrupt change of the activity level at a rotation period of ~10d. Our more than three times larger sample increases the statistical significance of this finding.