variable in Perseus, whose primary component is a B-type main sequence star with an apparent magnitude of 6.69. Phi Persei (Dajiangjunbei) is a double star, although the two components do not eclipse each other. The primary star is a Be star of spectral type B0.5, possibly a giant star, and the secondary companion is likely a stellar remnant. The secondary has a similar spectral type to O-type subdwarfs.

With the historical name Mirfak