Supernovae, one of the most violent phenomena in astronomy, will be explored at CU-Boulder's Fiske Planetarium on Friday, April 4, and Tuesday, April 8, at 7:30 p.m. University of Colorado at Boulder astronomy Professor Richard McCray will delve into the subject of supernovae, looking at everything from ancient Chinese inscriptions to current observations of these rare stars and how these observations are used to measure the expansion of the universe.