I was just reading thru my copy of the newest addition of Popular Science about an exotic type of supernova that in theory would leave nothing behind; no neutron star and no black hole.

These hugely luminous supernova that are unusually long lived in terms of their brightness can perhaps be accounted for by a theory that stars with at least 150 times the mass of the Sun will blow themselves completely apart in runaway thermonuclear fusion processes.

Accordingly, as the requisite star evolves and nears the end of its life, the temperature in the deep interior of the star reaches 1.8 billion degrees F. At this temperature, the gamma rays within this ultra hot plasma state decay into electron positron pairs in a reverse process to Fermi-Dirac pair production. This sudden loss of gamma radiation of the corresponding wavelengths suddenly results in a strong loss of internal pressure thus causing the star to collapse. The temperature eventually reaches 5.4 billion degrees at which point a runaway fusion reaction occurs thus resulting in the complete fusioning of the stars material in a titanic explosion that dwarfs the energy release of conventional types of supernova.

These huge supernova are, accordingly, in part responsible for the production of the heavy elements out of which planets including Earth are made. The power of these supernova astounds me. They must be at least 100 times the yield of a Type Ia or carbon detonation supernova. These huge supernova in theory explode in an essentially spherically symmetric pattern.

The observational astronomers are looking for the degree of spectral emissions of radioactive Nickel which is a product of such supernova explosions.

The detection of high energy photons in the gamma ray energy range by the GLAST gamma ray telescope may help in the discovery of more candidates for these exotic supernova and perhaps even more energetic events yet.