Radial velocity measurements of B stars in the Scorpius-Centaurus association

Abstract

We derive single-epoch radial velocities for a sample of 56 B-type stars members of the subgroups Upper Scorpius, Upper Centaurus Lupus and Lower Centaurus Crux of the nearby Sco-Cen OB association. The radial velocity measurements were obtained by means of high-resolution echelle spectra via analysis of individual lines. The internal accuracy obtained in the measurements is estimated to be typically 2-3 km/s, but depends on the projected rotational velocity of the target. Radial velocity measurements taken for 2-3 epochs for the targets HD120307, HD142990 and HD139365 are variable and confirm that they are spectroscopic binaries, as previously identified in the literature. Spectral lines from two stellar components are resolved in the observed spectra of target stars HD133242, HD133955 and HD143018, identifying them as spectroscopic binaries.