Sheliak

Sheliak is a blue main-sequence star (spectral type B7V) about 960 light-years away. With an apparent magnitude of 3.53 it is easy to see with the naked eye under a dark sky.

Two stars so close that gas flows from one to the other.

Its light output is roughly 2,900 times that of the Sun (a rough estimate in visible light, calculated from brightness and distance).

From Germany (52° N) it rises and sets; it is best seen in the evening in July.