A gamma ray burst spotted earlier this year has been confirmed as the brightest ever recorded after receiving further analysis, BBC News reported.

A gigantic explosion of a star caused the burst of light, which was captured by space-based telescopes earlier this year. Researchers who analyzed the blast believe the star was about 20 to 30 times the mass of the sun.

Researchers also believe the explosion took place so deep in space the light took four billion years to be visible by Earth's telescopes. Their findings have been published in the journal Science.

"These events can happen in any galaxy at any time," said Paul O'Brien, professor of astronomy at the University of Leicester. "We have no way to predict them."

The research team analyzed data and images captured by NASA's Swift and Fermi telescopes based in space.

"The star was previously living quite happily, fusing material in its core. And then it ran out of fuel," said O'Brien, who was part of the Swift team. "We can see the decaying light - the remnants of both events - for weeks or months afterwards."

The study concluded the explosion itself would have only lasted a few minutes, but is reverberating throughout the universe's vast reaches. The star would then have collapsed into a black hole, followed by a wave of energy causing the star to expand outwards, creating a supernova.

This event was closer to Earth than most gamma-ray bursts, but the researchers said the planet will face no risk f radiation exposure. If such an explosion were to occur within 1,00 light years of Earth, the ozone would have taken considerable damage and life on the planet would face grave danger.

"The prediction is that there would be one [gamma-ray burst] close to the Earth to do us harm every 500 million years," said Prof O'Brien. "At some point in the Earth's history we probably were irradiated by a gamma-ray burst, and it will happen again at some point in the future... But the chances of it happening in our lifetime are very low."