The early-type close binary CV Velorum revisited

Abstract

Aims. Our goal was to improve the fundamental parameters of the massive close double-lined eclipsing B2.5V+B2.5V binary CV Velorum. Methods. We gathered new high-resolution echelle spectroscopy on 13 almost consecutive nights covering two orbits. We computed a simultaneous solution to all the available high-quality radial-velocity and light data with the latest version of the Wilson-Deviney code. Results. We obtained the following values for the physical parameters: M1 = 6.066(74) M� , M2 = 5.972(70) M� , R1 = 4.126(24) R� , R2 = 3.908(27) R� ,l ogL1 = 3.20(5) L� ,a nd logL2 = 3.14(5) L� . The quoted errors contain a realistic estimate of systematic uncertainties mainly stemming from the effective temperature estimation. We derived abundances for both components and found them to be compatible with those of B stars in the solar neighbourhood. We discovered low-amplitude periodic line-profile variations with the orbital frequency for both components. Their interpretation requires new data with a longer time span. The primary rotates subsynchronously while the secondary’s v sini and radius are compatible with synchronous rotation. We provide an update of the empirical mass-luminosity relation for main-sequence B stars which can be used for statistical predictions of masses or luminosities.