Most Massive Supernova

The brightest supernova ever recorded may in fact be a new kind of supernova, according to researchers using the Chandra X-ray Observatory. The supernova is so bright, researchers are having to revise their ideas of what happens when supermassive stars (100-150 sun masses) explode. SN2006gy is 240 million light years distant in the galaxy NGC 1260, and it shone brighter than the galactic center:

Previously, it was thought that these types of supernovas usually occur when massive stars exhaust their fuel and collapse under their own gravity, forming a black hole. In these cases, much of the mass of the star doesn't explode, but is captured by the black hole.

It's postulated that in the case of SN2006gy however, that the core of a the massive star produced so much gamma ray radiation that some of the energy from the radiation converted into particle and anti-particle pairs. The resulting drop in energy caused the star to collapse under its own huge gravity.

After this violent collapse, runaway thermonuclear reactions ensue and the star explodes, spewing the remains into space. The SN2006gy data suggest that spectacular supernovas from the first stars - rather than completely collapsing to a black hole as theorized - may be more common than previously believed.

"Of all exploding stars ever observed, this was the king," said Alex Filippenko, leader of the ground-based observations at the Lick Observatory at Mt. Hamilton, Calif., and the Keck Observatory in Mauna Kea, Hawaii. "We were astonished to see how bright it got, and how long it lasted."

Full details can be found here.