Ultra-luminous Type IIn Supernovae
An older book called Secrets of Space (Abacus books) was one of the first to split supernovae into different classes and more impressively describe the phenomenon of pair instability supernovae in all but name. It took another 20 years to see mention of this again, such was the uncertainty surrounding their existence. Indeed, they remained theoretical constructs until the discovery of SN 2007bi. Although not confirmed it is likely that this explosion represents the first observation of a type of supernova proposed in the 1960s. This chapter concerns this event and a few other explosions that may be related to this type of explosion.