Monster explosion: The gamma-ray burst's X-ray afterglow appears orange and yellow in this view that merges images from Swift's UltraViolet/Optical and X-ray telescopes.

Credit: NASA/Swift/Stefan Immler

Related articles

• Cosmic blast is 7.5-billion-year-old gamma ray burst
• Cosmic explosion from nowhere
• Ancient gamma-ray burst is most distant object ever seen
• Experts probe mystery of gamma ray bursts
• Black hole eats star, triggers gamma-ray flash

WASHINGTON DC: The U.S. space agency's Fermi telescope has detected a massive explosion in space which scientists say is the biggest gamma-ray burst ever detected.

The spectacular blast, which occurred in September in the Carina constellation, produced energies ranging from 3,000 to more than five billion times that of visible light, astrophysicists said.

"Visible light has an energy range of between two and three electron volts and these were in the millions to billions of electron volts," said astrophysicist Frank Reddy of U.S. space agency NASA.

Billions of electron volts

"If you think about it in terms of energy, X-rays are more energetic because they penetrate matter. These things don't stop for anything – they just bore through and that's why we can see them from enormous distances," Reddy said.

A team led by Jochen Greiner of Germany's Max Planck Institute for Extraterrestrial Physics determined that the huge gamma-ray burst occurred 12.2 billion light-years away. For comparison, the Sun is eight light-minutes from Earth, and Pluto is 12 light-hours away.

Taking into account the huge distance from Earth of the burst, scientists worked out that the blast was stronger than 9,000 supernovae – powerful explosions that occur at the end of a star's lifetime – and that the gas jets emitting the initial gamma rays moved at nearly the speed of light.

"This burst's tremendous power and speed make it the most extreme recorded to date," a statement issued by the U.S. Department of Energy said.

Biggest blast ever

Gamma-ray bursts are the universe's most luminous explosions, which astronomers believe occur when massive stars run out of nuclear fuel and collapse. Long bursts, which last more than two seconds, occur in massive stars that are undergoing collapse, while short bursts lasting less than two seconds occur in smaller stars.

In short gamma-ray bursts, stars simply explode and form supernovae, but in long bursts, the enormous bulk of the star leads its core to collapse and form a black hole, into which the rest of the star falls.

As the star's core collapses into the black hole, jets of material blast outward, boring through the collapsing star and continuing into space where they interact with gas previously shed by the star, generating bright afterglows that fade with time.