The Ursa Major Cluster (also known as Collinder 285) comprises the central part of the Big Dipper, itself a part of Ursa Major, the Greater Bear. The major stars in the picture are, from left to right, Dubhe (which is not part of the cluster), Merak, Phecda, Megrez, Alioth, and Mizar. Alcor, next to Mizar, is a member as well, as are several other stars in the picture. Averaging 80 light years away, 250 to 500 million years old, the cluster sprawls over a line some 30 light years long. It is at the heart of the much larger Ursa Major Stream, or Moving Group.

To see a labelled image, push the star:

Return to the Cluster Page.

By Jim Kaler. Return to STARS.