pair-instability supernova

A pair-instability supernova is a theoretical type of core collapse supernova in which sufficient pair production occurs (photons converting into electrons and positrons) to reduce internal radiation pressure to the point that the collapse continues. This results in runaway fusion, ejecting all the mass, with no stellar remnant remaining. This is theorized to occur in stars in a mass range from 130 to 250 solar masses, and not-too-high metallicity. Depending upon the mass (within this range), the supernova may be especially bright, a superluminous supernova. Various core-collapse-supernova types are presumed to result, depending upon the progenitor star. Such supernovae of high-mass stars producing no remnants are thought to be the reason for the upper mass gap (upper limit on the formation of stellar-mass black holes). No observed supernova has been confirmed by consensus to be a pair-instability supernova, but some are considered candidates, making them of research interest.