Study of starspot lifetimes based on light-curve amplitude and spectral type

sunspots are regions on the sun’s photosphere that appear darker than surrounding areas because they are cooler, usually by one or two thousand degrees Celsius. These spots are temporary phenomena caused by magnetic activity that results from the sun’s rotation and the complex circulation of hot gas below its surface, and they are accompanied by solar flares, mass ejections and other energetic phenomena. Other stars have similar regions, called starspots, and there have been some suggestions that in comparison the sun is comparatively quiescent. Starspots are interesting to stellar astronomers because they are informed by the star’s rotation and circulation, details that are otherwise difficult to discern. Although starspots are too small to be imaged directly by current telescopes, they can be inferred from variations in a star’s light.