Sometimes the super- prefix just isn’t extravagant enough, or it’s been used already, or linguistic inflation has set in. This term seems to be a product of all three, since it is an even more spectacular cosmic event than the well-known supernova. But perhaps the superlative is warranted in this case, as the last such event spotted from Earth was widely reported as being so intense that if it had happened near to us we would have fried (luckily, it happened long, long ago in a galaxy far, far away). Such cataclysmic explosions — the biggest bangs since the Big Bang, NASA called them, with perhaps permissible overstatement — are about a hundred times as powerful as the biggest supernovae and may be caused by the total collapse of a very large star. They have been suggested as a possible origin of intense bursts of gamma rays that have been observed by space-borne detectors since the 1970s. In January 1999 the source of one was seen for the first time as it was happening.
By this time, theorists had built up a picture in which GRBs [gamma-ray bursters] result from the collision of two high-density neutron stars or from a “hypernova” — the total collapse of a very massive star.
Science, Mar. 1999
Really big stars such as Eta Carinae may go out in an even more spectacular explosion called a hypernova. Such a hypernova could produce another phenomenon known as a gamma-ray burster, which sends powerful gamma radiation out into space.
Minneapolis Star Tribune, Jun. 1999