VOLUME-LIMITED SAMPLES OF SUPERNOVAE

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 n umber are either greatly subluminous or possessing highly unusual spec troscopic 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 brightnesse s with events as faint as -11.8. (3) Type Ia, Ib, and II events consti tute 24%, 14%, and 62% of the samples. (4) One-third of all supernovae cannot be placed in the traditional classification scheme due to unus ual properties. (5) A deep supernova search to M(B) = -12 will discove r subluminous events that can serve as well-observed prototypes of new explosion mechanisms.