Resolved double-lined spectroscopic binaries: A neglected source of hypothesis-free parallaxes and stellar masses

Double-lined spectroscopic binaries, once visually resolved (VB-SB2), provi de hypothesis-free orbital parallaxes and masses of both components. Unlike eclipsing-spectroscopic binaries for which many accurate masses are alread y known (Andersen 1991; Andersen 1997), the number of VB-SB2 remains rather small. This paper presents 40 such systems for which published visual obse rvations and radial velocities allow a simultaneous adjustment of both data sets. The precision of the individual masses as well as the evolution of t hat precision with respect to the published precision is investigated.