Imaging the cool stars in the interacting binaries AE Aqr, BV Cen and V426 Oph

TL;DR

This paper reviews the use of Doppler imaging techniques to map starspots on rapidly rotating cool stars in interacting binaries, highlighting their importance for understanding stellar magnetic activity and binary evolution.

Contribution

It provides a summary of indirect imaging methods applied to interacting binaries and presents visualizations of starspot distributions, emphasizing future research opportunities.

Findings

Starspot maps reveal complex magnetic activity patterns.

Magnetic activity influences binary evolution and accretion processes.

Imaging techniques can track starspot evolution over time.

Abstract

It is well known that magnetic activity in late-type stars increases with increasing rotation rate. Using inversion techniques akin to medical imaging, the rotationally broadened profiles from such stars can be used to reconstruct `Doppler images' of the distribution of cool, dark starspots on their stellar surfaces. Interacting binaries, however, contain some of the most rapidly rotating late-type stars known and thus provide important tests of stellar dynamo models. Furthermore, magnetic activity is thought to play a key role in their evolution, behaviour and accretion dynamics. Despite this, we know comparatively little about the magnetic activity and its influence on such binaries. In this review we summarise the concepts behind indirect imaging of these systems, and present movies of the starspot distributions on the cool stars in some interacting binaries. We conclude with a look at the future opportunities that such studies may provide.