Nonthermal Radio Emission from the Precataclysmic Binary System V471 Tauri

Recent observations have presented strong evidence for the existence of eclipses in the nonthermal radio emission from the precataclysmic binary system V471 Tau. In this paper we calculate the gyrosynchrotron emission from models assuming a dipole-shaped magnetosphere and a magnetized wind around the K dwarf. The model assumes that electrons are accelerated to mildly relativistic energies in the region where the magnetic fields of the two stars interact and become trapped in the K dwarf's magnetosphere. Comparison with the data indicates that azimuthal drift and energy loss lead to a region of enhanced density of mildly relativistic electrons, extending for over 100° in azimuth and preceding the white dwarf in phase. The data is best fitted by models assuming a power-law drop with azimuthal angle of this enhancement in mildly relativistic electron density.