Yesterday astronomers reported that a supernova, in the relatively nearby galaxy NGC 1260, has taken the record for the biggest supernova ever recorded. The supernova, SN 2006gy, was is a certain class of supernovas that is reserved only for stars of masses many order of magnitudes greater than our sun. Until September of last year, when this supernova was recorded, this class of supernova was purely a theoretical mathematic equation and only now has this class been seen in our piece of the universe.
A normal supernova is the process of a star dying by the collapse of its core from the lack of proper fuel created at its core. All previously recorded novas have been simply a collapse of the star and the creation of a black hole or neutron star. This type of supernova is the explosion of its particles and in the process it creates much heavier elements. This is said to be how most of the planetary materiel in the universe was created.
For more information on the death of stars look for the podcast Astronomy Cast