Originally Posted by Wiki

The kinetic energy released by the explosion has been estimated at 10^52 ergs [1] making it ten times more powerful than the typical supernova explosion which produces 10^51 ergs of energy.

Originally Posted by Chandra

The discovery of the supernova, known as SN 2006gy, provides evidence that the death of such massive stars is fundamentally different from theoretical predictions.

Originally Posted by Wiki

A pair instability supernova can only happen in stars that are very massive—having a range of around 130 to 250 solar masses. The massive star's core can produce high energy gamma rays which have a greater energy than the rest mass of two electrons (mass-energy equivalence). These gamma rays interact with electromagnetic fields of the atomic nuclei in the star, and become particle and anti-particle pairs of electrons and positrons. This causes the average travel distance of the gamma rays to become shorter, causing the temperature of the interior of the star to rise. This causes an even larger fraction of the produced gamma rays to be of high enough energy for pair production, causing more of the energy to be reabsorbed closer to its source. This creates a runaway reaction. As the energy is concentrated more and more into the star's core, the outer layers start to fall inwards, which then compress the core. The compression and heating produce a rapid (few seconds) thermonuclear burn or explosion of the core material. The explosion blows the star completely apart without leaving a black hole remnant behind.[6]