2000ApJ...529.1031R

Stellar flares with 10²-10⁷ times more energy than the largest solar flare have recently been detected from nine normal F and G main-sequence stars by Schaefer, King, and Deliyannis. These superflares have durations of hours to days and are visible from at least X-ray to optical frequencies. The absence of world-spanning aurorae in historical records and of anomalous extinctions in the geological record indicates that our Sun likely does not suffer superflares. In seeking to explain this new phenomenon, we are struck by its similarity to large stellar flares on RS Canum Venaticorum binary systems, which are caused by magnetic reconnection events associated with the tangling of magnetic fields between the two stars. The superflare stars are certainly not of this class, although we propose a similar flare mechanism. That is, superflares are caused by magnetic reconnection between fields of the primary star and a close-in Jovian planet. Thus, by invoking only known planetary properties and reconnection scenarios, we can explain the energies, durations, and spectra of superflares as well as explain why our Sun does not have such events.