The Asiago Supernova Catalog is used to carry out a comparative study of supernova absolute-magnitude distributions .
An overview of the absolute magnitudes of the supernovae in the current observational sample is presented , and the evidence for subluminous and overluminous events is examined .
The fraction of supernovae that are underluminous ( M _ { B } > -15 ) appears to be higher ( perhaps much higher ) than one fifth but it remains very uncertain .
The fraction that are overluminous ( M _ { B } < -20 ) is lower ( probably much lower ) than 0.01 .
The absolute-magnitude distributions for each supernova type , restricted to events within 1 Gpc , are compared .
Although these distributions are affected by observational bias in favor of the more luminous events , they are useful for comparative studies .
We find mean absolute blue magnitudes ( for H _ { 0 } = 60 ) of -19.46 for normal Type Ia supernovae ( SNe Ia ) , -18.04 for SNe Ibc , -17.61 and -20.26 for normal and bright SNe Ibc considered separately , -18.03 for SNe II-L , -17.56 and -19.27 for normal and bright SNe II-L considered separately , -17.00 for SNe II-P , and -19.15 for SNe IIn .