Filippenko 9417213 This research represents a concentrated effort to determine the nature of the progenitor stars, the explosion mechanisms, and the nucleosynthetic products of different types of supernovae. The results will have broad implications for topics as diverse as the chemical evolution of galaxies, the birthrate of pulsars, and cosmology. The adopted approach is largely observational, coupled with theoretical modeling. A vigorous search for new supernovae in nearby galaxies will be conducted with an automated imaging telescope at Leuschner Observatory, thereby extending an effort that began over a year ago. Multi-color, long-term light curves of all sufficiently bright supernovae will be obtained with a second robotic telescope at Lick Observatory. High-quality optical spectra will also be obtained with state-of-the-art equipment in order to study the temporal evolution and statistical properties of supernovae. Thorough analysis of the data should lead to the development of a more complete classification scheme that focuses on fundamental parameters. Besides providing deeper insights into their origins and physical characteristics, quantitative assessment of the observed properties of nearby supernovae should improve the potential of supernovae for cosmological distance determinations. The newly commissioned Keck 10-meter telescope will be used to obtain spectra of very distant supernovae, in an attempt to measure the expansion rate and overall curvature of the Universe. ***
