Program: GS-2011B-Q-1

We request 10 hours of GMOS spectroscopy to observe very young supernovae discovered by our CHilean Automated Supernova sEarch (CHASE). CHASE has found its niche in discovering very young supernovae using high cadence observations of target galaxies. Hence we request rapid ToO observations to obtain early phase spectra for a variety of supernovae types. These data will enable us to measure (for Type Ia and Type Ib/c supernovae) the abundances of various elements in the outer ejecta, which can be used to constrain explosion models. Moreover, early spectroscopy can reveal signatures related to the interaction of the SN ejecta with circumstellar material and give insights into the progenitor systems. In the case of hydrogen-rich core-collapse (Type II) supernovae, early observations can also provide important information regarding the physics of shock-breakout, and the pre-supernova density structure. Finally, spectra of supernovae at the earliest epochs will enable spectral classification necessary to enable efficient planning on various observational SN projects.