%0 Journal Article %T Energy Conservation in the Thin Layer Approximation: IV. The Light Curve for Supernovae %A Lorenzo Zaninetti %J International Journal of Astronomy and Astrophysics %P 37-58 %@ 2161-4725 %D 2021 %I Scientific Research Publishing %R 10.4236/ijaa.2021.111003 %X The light curves (LC) for Supernova (SN) can be modeled adopting the conversion of the flux of kinetic energy into radiation. This conversion requires an analytical or a numerical law of motion for the expanding radius of the SN. In the framework of conservation of energy for the thin layer approximation, we present a classical trajectory based on a power law profile for the density, a relativistic trajectory based on the Navarro-Frenk-White profile for the density, and a relativistic trajectory based on a power law behaviour for the swept mass. A detailed simulation of the LC requires the evaluation of the optical depth as a function of time. We modeled the LC of SN 1993J in different astronomical bands, the LC of GRB 050814 and the LC GRB 060729 in the keV region. The time dependence of the magnetic field of equipartition is derived from the theoretical formula for the luminosity. %K Supernovae: General %K Supernovae: (Individual: SN1993j) %K Gamma-Ray Burst: (Individual: GRB 050814) %K Gamma-Ray Burst: (Individual: GRB 060729) %U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=107126