of seconds for a star that has been stripped of its extended hydrogen-rich envelope by a strong stellar wind or mass exchange with a companion star in a binary system.

The photons observed by astronomers are emitted extremely far from the central regions. They carry information on the overall energetics, the explosion geometry, and on the products of explosive nuclear burning that is triggered by the passing shock wave. They can, however, only provide weak constraints on the inner workings of the supernova. Direct observational information on the supernova mechanism can be gained only from neutrinos and gravitational waves that are emitted directly in the supernova core. Detailed computational models are required for gaining theoretical insight and for making predictions that can be contrasted with future neutrino and gravitational-wave observations from the next core-collapse supernova in the Milky Way.

Supernova Energetics and Mechanisms
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Core-collapse supernovae are “gravity bombs.” The energy reservoir from which any explosion mechanism must draw is the gravitational energy released in the collapse of the iron core to a neutron star: $\sim$$3\times10^{53}\,\mathrm{erg}$ ($3\times 10^{46}\,\mathrm{J}$), a mass-energy equivalent of $\sim$$0.15M_\odot c^2$. A fraction of this tremendous energy is stored initially as heat (and rotational kinetic energy) in 