Surface activity of a Rossby sequence of cool Hyades stars

TL;DR

This study investigates surface activity in 21 Hyades dwarf stars, revealing that their activity levels mainly depend on convective motions characterized by Rossby numbers, with a lesser influence from surface rotation.

Contribution

It provides the first quantitative analysis of surface activity in a sequence of Hyades stars, emphasizing the dominant role of convective turnover time over rotation.

Findings

Surface activity correlates strongly with convective motions.

Rossby number dependencies are primarily driven by convection.

Surface rotation has a secondary or inverse effect on activity.

Abstract

Aims. The Hyades cluster is key for the study of rotational, activity, and chemical evolution of solar-like low-mass stars. Here we present quantitative surface-activity information for a sequence of 21 Hyades dwarf stars. Conclusions. We conclude that the Rossby-number dependencies of the surface activity tracers A(Li), R(IRT), and B on our Hyades dwarf sequence primarily originate from convective motions, expressed by its turnover time, and only to a smaller and sometimes inverse extent from surface rotation and its related extra mixing.