2004MNRAS.348..285W

By analogy to Jovian radio emissions powered by the electromagnetic interaction between Jupiter and its moons, we propose that close magnetic-non-magnetic white dwarf pairs and white dwarf planetary systems are detectable radio sources. A simple model is developed to predict the flux densities of radio emission generated by a loss-cone-driven electron-cyclotron maser. The radio emission from these systems has high brightness temperatures, is highly polarized, and varies on a periodic cycle following the orbital rotation. Masers from magnetic-non-magnetic white dwarf pairs, with orbital periods ≲10 min, are expected to be detectable over a wide range of radio frequencies. Terrestrial planets in close orbits about magnetic white dwarfs, with orbital periods ≲30 h, can also produce detectable radio emission, thus providing a means to identify Earth-sized extrasolar planets.