Nucleosynthesis constraints through very late observations of type Ia supernovae

Abstract:  Type Ia supernovae are likely the thermonuclear explosion of relatively massive white dwarfs. The ignition process for these normally inert objects remains a mystery. The community has identified several plausible ignition scenarios (accretion from a companion, merger of white dwarfs, compression through the explosion of a helium shell, etc.). The current plethora of viable models matches the data of the first weeks to months - making it hard to distinguish between them. In this talk, I will show that, while the current feasible models produce very similar amounts of Ni56, their Ni57 and Co55 yields can be very different. These isotopes have decay chains with half-lives of hundreds of days leading to light-curves differences in very late epochs of 500 days and more. I will discuss the work on the extremely late light-curves (>1000 days) of the very nearby SN2011fe and the challenges faced. I will conclude by discussing how JWST will provide crucial observing capabilities that will finally allow us to rule out several of the proposed models.