A comparative study of supernova light curves.

Mean light curves of Type I, II-P ("plateau"), and II-L ("linear") supernovae are plotted on a common scale and directly compared. The Type II-P light curve has a distinctive shape, but the shape of Type II-L bears a resemblance to that of Type I in both the B and V bands. The similarity raises the question of whether the underlying physics of Type II-L explosions is more like that of Type I than like that of Type II-P, contrary to the usual assumption. It is shown that for Tycho's and Kepler's supernovae, light-curve shape cannot distinguish between a Type I and Type II-L classification. The light curves of the principal examples of Zwicky's Type III, IV, and V supernovae are compared directly to the mean light curves of the main types. The authors suggest that these supernovae be referred to as II-pec, for "Type II peculiar".