On the evolution of close binaries with components of initial mass between 3 M and 12 M.

The evolution of components of close binary systems of intermediate mass and of Population I composition is numerically studied. The evolution of components of initial mass in the 5-10 solar mass range which experience two phases of Roche lobe overflow and become CO degenerate dwarfs is first discussed. Then, the evolution of components of initial mass 10.5, 11, and 12 solar masses is examined, and the conditions necessary for the formation of ONe degenerate dwarfs are studied. The evolution of models of three and four solar masses that experience only one phase of Roche-lobe overflow and become degenerate dwarfs containing substantial amounts of helium is explored. A mapping that relates the mass and composition of a degenerate remnant to the mass and status of its progenitor is provided. The responses to accretion of a Roche-lobe-filling component and of a cold CO degenerate dwarf are examined. Extensive comparisons with other types of stars are made.