W Crv: The shortest-period Algol with non-degenerate components?

Abstract

Radial velocity data for both components of W Crv are presented. In spite of providing full radial-velocity information, the new data are not sufficient to establish the configuration of this important system because of large seasonal light-curve variations which prevent a combined light-curve/radial-velocity solution. It is noted that the primary minimum is free of the photometric variations, a property which may help explain their elusive source. Photometrically, the system appears to be a contact binary with poor or absent energy exchange, but such an explanation - in view of the presence of the mass-transfer effects - is no more plausible than any one of the semi-detached configurations with either the more-massive or less-massive components filling their Roche lobes. Lengthening of the orbital period and the size of the less-massive component above its main-sequence value suggest that the system is the shortest-period (0.388 days) known Algol with non-degenerate components.