Shock Breakout and Early Light Curves of Type II-P Supernovae Observed
  with Kepler
  We discovered two transient events in the Kepler field with light curves that
strongly suggest they are type II-P supernovae. Using the fast cadence of the
Kepler observations we precisely estimate the rise time to maximum for KSN2011a
and KSN2011d as 10.5$\pm 0.4$ and 13.3$\pm 0.4$ rest-frame days respectively.
Based on fits to idealized analytic models, we find the progenitor radius of
KSN2011a (280$\pm 20$ R$_\odot$) to be significantly smaller than that for
KSN2011d (490$\pm 20$ R$_\odot$) but both have similar explosion energies of
2.0$\pm 0.3\times 10^{51}$ erg.
  The rising light curve of KSN2011d is an excellent match to that predicted by
simple models of exploding red supergiants (RSG). However, the early rise of
KSN2011a is faster than the models predict possibly due to the supernova
shockwave moving into pre-existing wind or mass-loss from the RSG. A mass loss
rate of $10^{-4}$ M$_\odot$ yr$^{-1}$ from the RSG can explain the fast rise
without impacting the optical flux at maximum light or the shape of the
post-maximum light curve.
  No shock breakout emission is seen in KSN2011a, but this is likely due to the
circumstellar interaction suspected in the fast rising light curve. The early
light curve of KSN2011d does show excess emission consistent with model
predictions of a shock breakout. This is the first optical detection of a shock
breakout from a type II-P supernova.
