Mizar

Mizar is a blue-white main-sequence star (spectral type A2V) about 83 light-years away. With an apparent magnitude of 2.23 it is easy to see even from a city.

Together with Alcor it forms the "horse and rider" – once used as an eyesight test.

Its light output is roughly 70 times that of the Sun (a rough estimate in visible light, calculated from brightness and distance).

From Germany (52° N) it never sets: it stays above the horizon all year.