B Persei

b Persei is a spectroscopic triple star in the constellation Perseus. Its apparent magnitude is 4.60, making it visible to the naked eye. It is about 320 light years away.
In addition to the primary, an A-type giant, there is a smaller and cooler companion in a 1.53 day orbit, probably an F-class star around absolute magnitude 3.0, and a more distant companion in an orbit calculated to be 702 days long. The close binary pair forms a rotating ellipsoidal variable with a 1.53 day period. Star C forms an Algol-type variable system with the close binary, showing both primary eclipses and secondary eclipses. Timings of the eclipses show a 704.5-day period.