A New Angular Momentum Loss Mechanism for Cataclysmic Variables

It is well known that there is mass outflow in cataclysmic variables, since IUE observations show P Cyg profiles of various high-excitation lines of C IV and S IV. It is proposed here that these outflows are hydromagnetic winds from accretion disks. The winds extract angular momentum from these systems and therefore drive secular evolution. Disk winds are preferred to winds from the secondary star because of the lower disk surface gravities. Using values of the wind parameters inferred from observations, values are derived for the (time-averaged) induced rate of mass transfer from the red dwarf secondary which span the range inferred by Warner (1976 and 1987). It is shown that this theory accounts for both the IUE observations and the secular evolution of cataclysmic variables.