Rage against the dying of the light: the progenitors of Type Ia supernovae
Or Graur
Harvard Center for Astrophysics

Type Ia supernovae (SNe Ia) have famously been used as standard candles, a use that led to the discovery that the expansion of the Universe was accelerating under the influence of a mysterious new phenomenon called "dark energy." And yet, we still do not have a clear picture of the progenitors of SNe Ia, i.e., what types of star systems end up exploding as these supernovae. For obvious reasons, most observers study these supernovae when they are young and at their brightest. In my talk, I will present recent results from studies of SNe Ia before they exploded, as well as thousands of days after explosion. I will begin by showing how we can use pre-explosion images taken by chance with the Hubble Space Telescope to study the environment of the SNe hundreds of thousands of years before the explosion took place. And end by showing how Hubble Space Telescope observations of old SNe Ia, >1000 days after explosion, reveal a possible new correlation between the intrinsic luminosity of the SNe and the way their luminosity fades at these late times. If confirmed, this correlation could provide a brand new diagnostic of SN Ia progenitor, explosion, and nebular physics.