The Light and Velocity Curve Bumps for BW Vulpeculae

Abstract

BW Vulpeculae (HD 199140) is a well known Beta Cenhei star, with several unusual characteristics. It possesses the largest amplitude in both light and radial velocity variations, of any star in this classification. The most outstanding feature of the observations is a standstill or bump, on the light curve, accompanied by doubled lines in the radial velocity observations. In this paper, we have attempted to explain these phenomena with two different models. Firstly, the resonance mechanism, from Simon and Schmidt, and secondly, a non-linear calculation.