Astrophysicists have for the first time measured the rotation periods of stars in a cluster nearly as old as the Sun and found them to be similar. It turns out that these stars spin around once in about twenty-six 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.
Source:: Other Suns got the right spin