Alcor

Its story

Alcor is the little companion of Mizar in the handle of the Big Dipper, and ancient peoples used it as a test of eyesight — to separate the two stars was proof of a sharp eye. Its name comes from the Arabic «al-jawn», «the horse» or «the dim one». A white A-class star about 82 light-years away, a young flame orbiting Mizar in a multiple system: an inseparable pair to the unaided eye.