61 Cygni B is part of a binary star system in the constellation Cygnus the swan. Both 61 Cygni B and its companion 61 Cygni A are among the closest stars seen in the northern hemisphere. The stars orbit each other every 659 years, making them appear as two of the fastest-moving stars in the sky. Visible in dark skies, the stars are near the limit of what can be seen with the naked eye. Both stars in 61 Cygni are orange dwarfs, intermediate between larger stars like the Sun and smaller red dwa…