Superflares on Late-Type Stars

We present the results of an extensive survey of superflares on late-type stars (G, K, and M-type main sequence stars) using the Kepler satellite data. Wefound about 6,800 superflares on late-type stars from the data of about 120,000 stars observed over 500 days. The total bolometric energy of superflares in oursample ranges from 10³² erg to 10³⁶ erg. Our data suggest that the occurrencefrequency of superflares depends on the surface temperature and the rotationperiod of stars. Superflares on M-type stars occur about 10-100 times morefrequently than those on G-type stars. Our results suggest that the average frequency ofsuperflares releasing 10³⁴-10³⁵ erg of energy (100-1,000 times larger than the largestsolar flares) on M-type stars and Sun-like stars is once in 10 years and once in a few thousand years respectively.