Pair-instability supernova

A stellar explosion in which electron–positron pair production softens a massive star’s core, triggering runaway oxygen fusion that completely disrupts the star without leaving a compact remnant.

Electron–positron pair production: The conversion of high-energy photons into an electron and a positron. Pair creation removes pressure-supporting photons from the core and softens its equation of state.
Massive star: A star massive enough to evolve rapidly and eventually develop a hot, dense core that can undergo advanced nuclear burning. Pair-instability progenitors begin as massive stars capable of building large oxygen-rich cores.
SN 2007bi: An unusually luminous supernova whose slow evolution and inferred large radioactive nickel yield prompted a pair-instability interpretation. It became a prominent candidate because its light curve and energetics suggested an exceptionally massive exploding core.
Nickel-56: A radioactive nickel isotope that decays through cobalt-56 to iron-56. Its decay can power a candidate explosion’s long-lasting luminosity when produced in large quantities.
Pulsational pair-instability supernova: A sequence of eruptions caused by pair instability that ejects stellar layers but leaves a core to collapse later. It shares the pair-production trigger but does not initially destroy the star completely.
Radiation pressure: Pressure exerted by photons through their momentum and interactions with matter. Radiation pressure supports the hot core until pair production reduces its effectiveness.
Stellar evolution: The sequence of physical changes a star undergoes as it forms, burns nuclear fuel, and reaches its final state. The star’s prior evolution determines whether its core enters the pair-instability regime.
SN 2016iet: A luminous, long-lasting supernova with a low-metallicity environment and an unusually large separation from its host galaxy. Its prolonged emission and inferred progenitor properties have been compared with pair-instability models.
Cobalt-56: A radioactive isotope of cobalt produced by nickel-56 decay and subsequently decaying to iron-56. Its radioactive decay contributes to the observed fading of supernova light.
Black hole: A region of spacetime whose gravity prevents anything, including light, from escaping beyond its event horizon. Stars above the full-disruption regime may avoid a pair-instability supernova and instead leave a black hole.

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