Program: GN-2009B-Q-20

Title:Echoes of Historic Milky Way Supernovae: Spectroscopy of the Cas A, Tycho, 3C 58, and Crab SNe at Maximum Light.
PI:Armin Rest
Co-I(s): Marcel Bergmann, Doug Welch, Andy Becker, Stephane Blondin, Peter Challis, Alejandro Clocchiati, Kem Cook, Guillermo Damke, Ryan Foley, Arti Garg, Mark E. Huber, Tom Matheson, Dante Minniti, Knut Olsen, Jose Luis Prieto, Brendan Sinnott, R. Chris Smith, Nicholas Suntzeff, Michael Wood-Vasey

Abstract

Our group has embarked on an imaging and spectroscopic survey to find and track light echoes of the original light from Galactic Supernovae, and we have already found several associated with the Tycho supernova of 1572 and Cas A Supernova of 1680. Our survey continues in 2009B with four Northern supernovae to be imaged with the KPNO 4m/MOSAIC camera. Here we propose Gemini/GMOS-N spectroscopic follow-up of the brightest echoes found. These echoes are moving with an apparent motion of ~30"/year, with knots of reflected light brightening and fading on ~monthly timescales, so they need to be treated as Targets of Opportunity. Since the SN light is reflected without thermal reprocessing, spectroscopy of the echoes reveals the mean SN spectrum around maximum luminosity, which we will use to determine the SN type and sub-type. We will also investigate whether we can find signs of asymmetry in the SN explosions by comparing the spectra of a single SN observed from different angles, as viewed from the locations of the dust clouds causing the echoes.