Super Supernovae

Every supernova is a brilliant beacon — a stellar explosion that can outshine an entire galaxy. But in recent years, astronomers have logged a few dozen supernovae that take “brilliant” to extremes — they shine anywhere from about 10 to hundreds of times brighter than a typical supernova. And theorists are still trying to understand why.
The first examples of “superluminous” supernovae were discovered more than a decade ago by Robert Quimby, a graduate student at the University of Texas at Austin. He was looking for supernovae across large patches of the sky when he discovered a couple of exceptionally bright examples. Since then, other astronomers have joined the search, leading to many new discoveries.
These super-bright explosions appear to come in two varieties. One contains a lot of hydrogen — the element that makes up the bulk of most stars. The other type shows no hydrogen.
The hydrogen-rich variety may involve a shell or bubble of hydrogen gas around the star that was expelled