I recently got interested in reading about Pair-Instability Supernovae. What I don't understand is: "...triggering a collapse that vaporises the star. This pair-instability supernova creates a larger quantity of elements heavier than helium ("metals") than in other types of supernova and not leaving a black hole remnant." - Wikipedia (http://en.wikipedia.org/wiki/Supernova#Pair-instability_type) How is there no remnant left behind (i.e. black hole)? I always thought the greater the mass of the star, the greater the certainty of leaving a black hole.