phi piscium (phi psc, φ piscium, φ psc) is a binary star system approximately 380 light years away in the constellation pisces. it consists of phi piscium a, with a spectral type of k0iii, and phi piscium b. phi piscium a possesses a surface temperature of 3,500 to 5,000 kelvins. some suggest the only visible companion in the phi piscium b sub-system is a late f dwarf star, while others suggest it is a k0 star. the invisible component of the phi piscium b sub-system is proposed to have a spectral type of m2v. the star system has a period of about 20½ years and has a notably high eccentricity of 0.815.