大熊座移動星群
Alcor A and B are situated 1.2 light years away from, and are co-moving with, the Mizar quadruple system, making the system the second known stellar sextuplet—only Castor is closer. The Mizar-Alcor stellar sextuple system belongs to the Ursa Major Moving Group, a stellar group of stars of similar ages and velocities, and the closest cluster-like object to Earth.