Phi Persei
Phi Persei is a Class B2Vpe, fourth-magnitude star in the constellation Perseus. Phi Persei is binary consisting of a blue main sequence primary of class B2 and an apparent magnitude of 4.01 and a hot subdwarf secondary. Due to its rapid rotation, the primary has a polar radius about and an equatorial radius of about. Phi Persei is also a variable star with rapid variations in its brightness and spectrum. The Phi Persei stellar system is located about 716 light-years from Earth.Naming
followed Ptolemy in treating φ Persei as being in Andromeda and gave it the designation 54 Andromedae. It is isolated from the main stars of Perseus, but lies within its formal borders.
In Chinese, 天大將軍, meaning Heaven's Great General, refers to an asterism consisting of φ Persei, γ Andromedae, 51 Andromedae, 49 Andromedae, χ Andromedae, υ Andromedae, τ Andromedae, 56 Andromedae, β Trianguli, γ Trianguli and δ Trianguli. Consequently, the Chinese name for φ Persei itself is 天大將軍二.
