Complex sentence: Hypernova (pl. hypernovae) refers to a type of supernova explosion with an energy of over 100 supernovae (over 10 48 joules); such explosions are believed to be the origin of long-duration gamma-ray bursts.
Split into simpler sentences: Hypernova (pl. hypernovae) refers to a type of supernova explosion with an energy substantially higher than standard supernovae. Such explosions are believed to be the origin of long-duration gamma-ray bursts.