THE URSA MAJOR CLUSTER

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. All 13 stars (including double Mizar) in the cluster are indicated by name. HR refers to the Yale Bright Star Catalogue. The six-digit numbers are from the spectroscopic Henry Draper Catalogue. The stars with proper names are all class A. HR 4867 is a class F dwarf, while the two faintest stars (HD 109011 and HD 110463) are both class K dwarfs. HD 115043 is a class G dwarf very similar to the Sun. Averaging 80 light years away, the cluster sprawls over a line some 30 light years long.