γ Per: Bright, but Ill-Understood

Abstract

γ Per looks like an unexceptional composite–spectrum binary, and has habitually been classified as G8 III+A3 V. Nevertheless, previous studies have produced conflicting results, of component masses that are uncomfortably high, or luminosities that are too large, or (most recently) showing that there is nothing abnormal about the components after all. However, new high-precision CCD spectroscopy and isolation of the secondary spectrum finds that mass of the giant is 3.9 M_⊙, which is indeed greater than would be expected from its published spectral type, and that both components have somewhat enhanced luminosities, thus re-opening the question of the origin and evolution of this somewhat unusual system.