A new mechanism for stellar radio bursts : the fully relativistic electron maser.

A new mechanism similar to cyclotron maser instability is proposed for explaining nonthermal emissions that have recently been detected from UV Cet stars or RSCVn and AM Her binaries. The analogies and differences between planetary radio emission and stellar radio bursts are reviewed, and the theory of maser instability is developed for the case of moderately relativistic electrons, which are expected to be found at least in the environments of the abovenamed stellar objects and binary systems. The results obtained from a parametric study of the maser mechanism under conditions believed to prevail in star and binary environments are presented and discussed.