of this star is about 0.92 mas. It has an estimated age of 300 million years. Gamma Ursae Majoris is also an astrometric binary: the companion star regularly perturbs the Ae-type primary star, causing the primary to wobble around the barycenter. From this, an orbital period of 20.5 years has been calculated. The secondary star is a K-type main-sequence star that is 0.79 times as massive as the Sun, and with a surface temperature of . References A-type main-sequence stars Ursa Major Moving Group Phecda Ursae Majoris, Gamma Big Dipper Ursa Major (constellation) Durchmusterung objects Ursae Majoris, 64 103287 058001 4554 Astrometric binaries