Mass and angular momentum loss during RLOF in Algols

Abstract

We present a set of evolutionary computations for binaries with a B-type primary at birth. Some liberal computations including loss of mass and angular momentum during binary evolution are added to an extensive grid of conservative calculations. Our computations are compared statistically to the observed distributions of orbital periods and mass ratios of Algols. Conservative Roche Lobe Over Flow (RLOF) reproduces the observed distribution of orbital periods decently but fails to explain the observed mass ratios in the range 0.4-1. In order to obtain a better fit the binaries have to lose a significant amount of matter, without transferring too much angular momentum.