starspots tagged posts

About eight percent of red giants are covered by sunspot-like, dark areas; these stars rotate faster than others of their kind. Starspots are more common among red giant stars than previously thought. Astronomers report that approximately eight percent of red giants exhibit such spots. Although red giants are generally regarded as slowly rotating stars, those with starspots are apparently an exception. The new publication offers a comprehensive analysis of the reasons for their short rotation periods.

Among the Sun’s most striking features are its sunspots, relatively darker areas compared to the rest of the surface, some of which are visible from Earth even without magnification...

False-colour image of the stellar open cluster M67. Red, green, blue composite based on Johnson B, V and G bandpass images. Captured with WiFSIP/STELLA on Tenerife. Credit: AIP

It turns out these stars spin around once in ~26 days – just like our Sun. This discovery significantly strengthens what is known as the solar-stellar connection, a fundamental principle that guides much of modern solar and stellar astrophysics. This principle – that the Sun is a star – was only proved in the 19th century when distances to the nearest stars were measured. It enables us to use the Sun, the only star we can observe in detail, to study processes occurring on other stars, and conversely, to use other stars to infer the past and future of our Sun...