A quest for activity cycles in low mass stars

TL;DR

This study analyzes long-term photometric data of ultrashort-period low-mass stars to identify activity cycles, revealing a correlation between rotation rates and cycle lengths, with the shortest cycles on the fastest rotators.

Contribution

It provides new observational evidence of activity cycles in ultrashort-period low-mass stars, especially highlighting the shortest cycles on the fastest rotators.

Findings

A loose correlation between rotation rate and cycle length exists.

The shortest activity cycles are 1-2 years on the fastest rotators.

Cycle lengths are consistent across different evolutionary states.

Abstract

Long-term photometric measurements in a sample of ultrashort-period (P~0.5 days or less) single and binary stars of different interior structures are analysed. A loose correlation exists between the rotational rate and cycle lengths of active stars, regardless of their evolutionary state and the corresponding physical parameters. The shortest cycles are expected on the fastest rotators in the order of 1-2 years, which is reported in this paper.