XX Tri: Watching the Sky’s Most Spotted Star Evolve Over 40 Years

This study tracks 40 years of brightness changes in XX Tri, a highly active red giant star covered in dark starspots. Researchers identified multiple magnetic cycles, surface temperature increases, and solar-like differential rotation. Their findings suggest that the star’s unspotted brightness has increased over time, challenging assumptions in spot modeling and offering insights into stellar magnetism in binary systems.