  Flares that are orders of magnitude larger than the most energetic solar
flares are routinely observed on Sun-like stars, raising the question of
whether the same physical processes are responsible for both solar and stellar
flares. In this letter we present a white-light stellar superflare on the star
KIC9655129, observed by NASA's Kepler mission, with a rare multi-period
quasi-periodic pulsation (QPP) pattern. Two significant periodic processes were
detected using the wavelet and autocorrelation techniques, with periods of 78
+/- 12 min and 32 +/- 2 min. By comparing the phases and decay times of the two
periodicities, the QPP signal was found to most likely be linear, suggesting
that the two periodicities are independent, possibly corresponding either to
different magnetohydrodynamic modes of the flaring region, or different spatial
harmonics of the same mode. The presence of multiple periodicities is a good
indication that the QPPs were caused by magnetohydrodynamic oscillations, and
suggests that the physical processes in operation during stellar flares could
be the same as those in solar flares.
