The Spin-up of a Star Gaining Mass in a Close Binary System on the Thermal Time Scale

Abstract We investigate the exchange of mass in a binary system as channel through which Be star can receive rapid rotation. The mass-transfer phase massive close Hertzsprung-gap is accompanied by spinning up accreting component. consider case when component increases 1.5 times. acquires and angular momentum while state critical 50 Meridional circulation effectively transports inside during thermal timescale after end phase. As result transfer, rotation typical classical stars.