The Orbit of the Classical Cepheid AW Persei Revisited

Abstract

We have obtained new velocity data for the classical Cepheid AW Persei and used them to derive a new orbit for the binary star system of which it is part. The orbital period (40 yr) is slightly longer than the previously determined orbit. The lower limit to the mass of the secondary from the new mass function is 6.6 M_solar. This is much larger than the mass inferred from the spectral type of the companion, 4.0 M_solar. This implies that the secondary is itself a binary in a short-period orbit. We have used an IUE high-resolution spectrum to confirm the spectral contributions from the Cepheid and the hottest companion at 2600 Å. Based on observations from David Dunlap Observatory.