  We have computed the time evolution of bolometric, far-infrared, Halpha line,
ultraviolet (both intrinsic and escaping the star forming region) and the
nonthermal radio continuum luminosities for continuous and constant star
formation. The luminosity rises to a plateau value and declines after the
termination of starburst, but only gradually. The time evolution profiles are
broad and different for different star formation indicators. The broad profiles
lead to uncertainties in the star formation rate derived depending on the
initial mass function, duration of starburst, its distribution and the
observational epoch.
