Re-analysis of close binary systems

Abstract

The facts indicating that large line-forming regions occur among the best-studied close binaries are outlined. It is pointed out that emission lines are often redshifted while absorption lines are blueshifted, emission lines can brighten during occultattions, the amplitudes of the periodic Doppler shifts and systemic velocities vary from line to line, there are often significant phase offsets between minimum light and zero-radial velocity, and the lines' Doppler shifts are often far from periodic. The extent of the line-forming regions is estimated, the corotation of the solar wind is discussed as a testing ground for more rapidly rotating systems, and the corotation problem of close binaries including Cyg X-1, SS 433, A 0620-00, and DQ Her is considered. It is concluded that the winds of Wolf-Rayet stars are centrifugally driven, their mass-loss rates were overestimated, and seemingly single massive stars can hide a compact companion.