Mizar (Zeta Ursae Majoris; z UMa)

The fourth-brightest star in the constellation Ursa Major, an A star of magnitude 2.3. It forms an optical pair (i.e. not a true binary system but a mere coincidence in the line of sight) with the fourth magnitude star Alcor. Mizar also has a true fourth magnitude companion, and both stars are also spectroscopic binaries. The Arabic name means "girdle".