Systemic Mass Loss

Abstract

The decrease of total mass by ejection past the outer Lagrangian points is a distinct possibility, probably a necessity, in the explanation of late phases of evolution, and some instances have been mentioned earlier. One indication noted by van den Heuvel (1969) may apply to a large fraction of the binary population, namely that much fewer semi-detached pairs are observed among early-type spectroscopic binaries than would be expected to exist as normal and long-lived remnants of case B mass transfer, even if the decrease of the formation rate of young stars were considered to be insignificant. The transfer moves the erstwhile secondary up the main sequence as an unevolved star of increased mass. Systemic loss mass may account for the discrepancy of occurrence as it removes the descendant objects off the domain of easily discovered, luminous spectroscopic pairs.