  Photometry data were collected from the literature and analyzed for
supernovae that are thought to have a gamma-ray burst association. There are
several gamma-ray burst afterglow light curves that appear to have a supernova
component. For these light curves, the supernova component was extracted and
analyzed. A supernova light curve model was used to help determine the peak
absolute magnitudes as well as estimates for the kinetic energy, ejected mass
and nickel mass in the explosion. The peak absolute magnitudes are, on average,
brighter than those of similar supernovae (stripped-envelope supernovae) that
do not have a gamma-ray burst association, but this can easily be due to a
selection effect. However, the kinetic energies and ejected masses were found
to be considerably higher, on average, than those of similar supernovae without
a gamma-ray burst association.
