Supernovae

Abstract

Observations of Type Ia supernovae (SN Ia) combined with modeling of dynamics, light curves and spectra continue to point to the difficult conclusion that SN Ia result from degenerate ignition in a carbon/oxygen white dwarf of the Chandrasekhar mass. Such a model accounts well for the “normal” SN Ia and for the observed dispersion exemplified by the light curve amplitude-shape relation. The criterion that the white dwarfs involved in this process grow to nearly 1.4 M ⊙ continues to provide a great challenge to understanding the binary stellar evolution involved. The so-called “supersoft X-ray sources” may provide an important new population of SN Ia progenitors. Other techniques are being developed that may constrain the binary evolution.