REANALYSIS OF CLOSE BINARY-SYSTEMS

Line-forming regions around close binaries with strong winds ( {Mathematical expression}/4πr*v∞≳10-4 g cm-2) are large in extent compared with the stars, large enough to screen them. Their orbitally-modulated Doppler shifts can overestimate the mass function, because of a larger rotational lever arm. In particular, most of the black-hole candidates need not involve companions more massive than a neutron star. The solar-wind problem is reconsidered. An extrapolation to Wolf-Rayet stars suggests that their winds are centrifugally driven. Their mass-loss rates tend to have been overestimated. Seemingly single (massive) stars can hide a (compact) companion. © 1990 Kluwer Academic Publishers.