Part of the show Catalysts for Cleaner Environments and Future Energy
A supernova is basically an exploding star, the explosion can be cause for a variety of reasons. A very important type is 1a, this is caused where an old star ember called a white dwarf is slowlyy aquiring matter from another star (probably a red giant), eventually it gets so heavy that it can't support itself and it collapses. In this collapse carbon and oxygen start to fuse together creating heavier elements ( almost all the heavy elements in the universe were made in supernovae), this releases an immense amount of energy and blows the star apart creating an explosion 5 billion times brighter than the sun.
Unfortunately Andrew Howell has found what appears to be a type 1a supernova that is 2.2times brighter than the model says it should be possible to be. Maybe the star was spinning fast which allowed more matter to build up before it collapsed. This could mean that astonomer's have observed lots of supernovae that are actually at lot further away than was calculated and cosmolgists are going to have to look at their data, and possibly their conclusions very carefully.