I have constructed two volume-limited samples of supernovae; the first of extragalactic events with a distance modulus less than 29 mag (H_0_ = 75), and the second of Galactic supernovae from the last millennium within 4 kpc. Out of 33 total events in these samples, a surprising number are either greatly subluminous or possessing highly unusual spectroscopic or photometric properties. My conclusions are as follows. (1) A significant fraction (probably the majority) of Type Ia events are not standard candles, with most being subluminous by from 1 to 6 mag. (2) The luminosity function of Type II events is roughly flat from M_B_ equal to -18.3 to -15.2 and then rises sharply to lower brightnesses with events as faint as -11.8. (3) Type Ia, Ib, and II events constitute 24%, 14%, and 62% of the samples. (4) One-third of all supernovae cannot be placed in the traditional classification scheme due to unusual properties. (5) A deep supernova search to M_B_ = - 12 will discover subluminous events that can serve as well-observed prototypes of new explosion mechanisms.
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Bradley E. Schaefer (1996) studied this question.