Mizar

Mizar is a white star of spectral type A1VpSrSi at magnitude 2.27 in Ursa Major, famous as one of the most celebrated double stars in history. Its naked-eye companion Alcor (magnitude 4.0) sits just 12 arcminutes away. Mizar itself was the first telescopic double star discovered (1617), and each component is a spectroscopic binary — making the system at least a sextuple.

Mizar is the middle star of the Big Dipper's handle. Look carefully with the naked eye for the fainter companion Alcor just beside it — the Mizar-Alcor pair is one of the oldest known naked-eye double star tests. A small telescope at moderate magnification splits Mizar itself into two components separated by about 14 arcseconds. Best observed March through August.

The name Mizar comes from the Arabic 'mi'zar,' meaning 'girdle' or 'waistcloth.' The ability to see Alcor beside Mizar was used as an eyesight test by many cultures, including the Arabs, Romans, and Native Americans. Mizar A was the first spectroscopic binary star discovered, by Edward Pickering in 1889.