Corona Borealis, the Northern Crown, and Corona Australis, the Southern Crown, are two small constellations among the 48 listed by the 2nd-century astronomer Ptolemy. Corona Borealis, which generally represented the crown given by the god Dionysus to the Cretan princess Ariadne, is in the Northern Celestial Hemisphere, while Corona Australis, associated with Sagittarius or Centaurus, is in the Southern. Corona Borealis boasts the highly variable stars R and T Coronae Borealis and the huge Corona Borealis Supercluster. Corona Australis, lying alongside the plane of the Milky Way, hosts Epsilon Coronae Australis, the brightest example of a W Ursae Majoris variable in the southern sky. It also contains one of the closest star-forming regions to our Solar System, about 430 light years away—a dusty dark nebula known as the Corona Australis Molecular Cloud, with stars at their earliest stages. (See Corona Borealis and Corona Australis.)