Reality is indeed scarier than fiction - hypernovae are superenergetic events that are registered often in far away galaxies. Being hundreds of times more powerful than their already fierce supernovae cousins, hypernovae can shine as bright as the rest of the universe, emmiting incredible ammounts of gamma ray radiation. They are the greatest explosions in the universe since the Big Bang. If one were to detonate only a few thousand light years from Earth, the planet would probably be disintegrated by the furious blast. It's atmosphere and oceans would imediately boil and be spit away... then everything else would be dismantled... and everyone would die before anyone had a clue of what was happening. This image shows Earth an instant after being hit by the blast.

Done now. Oh, and it's not 100% astronomically accurate... stars are completelly random, and it's not like I did a simulation to figure how it would look like. :P

Ah, and I forgot to mention that Eta Carinae is only 7500 light years away and *could maybe* explode in a hypernova. Oh, and considering it's size, it's very short lived... so it may already have exploded (at least as supernova). [Of course, it takes 7500 years until we figure what happens there...]