Branch will further analyze the optical spectra of young supernovae, "young" referring to a time when one observes an "atmosphere" reminiscent of a star. The atmosphere is analyzed by a computer program for synthetic spectra. One goal is to determine the shells of various chemical abundances in the progenitor star by analysing the ejected distributions. A second topic concerns radio observations of historically observed supernovae. Second-epoch observations are already becoming feasible. Some aging stars are shattered by a giant explosion that we observe as a supernova. The explosion generates most of the elements of which the Earth and life is made. Observation of supernovae can inform us of the structure of the star that exploded and more generally about the evolution of stars and of our astronomical surroundings. Branch will continue two lines of investigating supernovae. Mainly, he will analyse the radiation spectrum emitted when a supernova is still young and bright. His work is very timely in view of the newly observed supernova. Branch will also investigate the radio emissions of slightly older supernovae to show how the newly exploding supernovae are transformed into the still older nebular supernova remnants of which the Crab Nebula is a famous example.
