  Long-term monitoring of the radio emission from supernovae with the Very
Large Array (VLA) shows that the radio ``light curves'' evolve in a systematic
fashion with a distinct peak flux density (and thus, in combination with a
distance, a peak spectral luminosity) at each frequency and a well-defined time
from explosion to that peak. Studying these two quantities at 6 cm wavelength,
peak spectral luminosity (L_{6 cm peak}) and time after explosion date (t_0) to
reach that peak (t_{6 cm peak} - t_0), we find that they appear related. In
particular, based on two objects, Type Ib supernovae may be approximate radio
``standard candles'' with a 6 cm peak luminosity L_{6 cm peak} \approx 19.9 X
10^{26} erg s^{-1} Hz^{-1}; also based on two objects, Type Ic supernovae may
be approximate radio ``standard candles'' with a 6 cm peak luminosity L_{6 cm
peak} \approx 6.5 X 10^{26} erg s^{-1} Hz^{-1}; and, based on twelve objects,
Type II supernovae appear to obey a relation L_{6 cm peak} \simeq 5.5 X 10^{23}
(t_{6 cm peak} - t_0)^{1.4} erg s^{-1} Hz^{-1}, with time measured in days. If
these relations are supported by further observations, they provide a means for
determining distances to supernovae, and thus to their parent galaxies, from
purely radio continuum observations.
