  An all-sky monitor with nuclear imaging spectroscopy is a promising tool for
the systematic study of supernova explosions. In particular, progenitor
scenarios of type-Ia supernovae, which are not yet well understood, can be
resolved using light curves in the nuclear gamma-ray band. Here we report an
expected result of an all-sky monitor with imaging spectroscopy using
electron-tracking Compton camera, which will enable us to observe nuclear
gamma-ray lines from type-Ia supernovae.
