Astronomers have discovered the brightest flash of light ever observed. It happened 2.4 billion light years from Earth and was probably triggered by the formation of a black hole, reports Phys.org. The burst of gamma rays (the most intense form of electromagnetic radiation) was first detected by orbiting telescopes on October 9, and its afterglow is still being observed by scientists around the world.

Astrophysicist Brendan O’Connor said the gamma-ray bursts, which last for hundreds of seconds, are thought to be caused by massive dying stars 30 times the size of our Sun. The star explodes into a supernova, collapses into a black hole, then the matter forms a disk around the black hole, falls inward, and erupts in a jet of energy that travels at 99.99% the speed of light.

The flash released photons carrying a record 18 teraelectronvolts of energy (18 with 12 zeros) and this affected long-wave radio communications in the Earth’s ionosphere.

“It’s really breaking records, both in the amount of photons, and the energy of the photons that are reaching us,” said O’Connor, who used infrared instruments on the Gemini South telescope in Chile to make the new observations.

“Something this bright, this nearby, is really a once-in-a-century event,” the astrophysicist added.

Research on gamma rays first began in the 1960s, when American satellites designed to detect whether the Soviet Union was detonating bombs in space discovered that such bursts were coming from beyond the Milky Way.

“Gamma-ray bursts in general release the same amount of energy that our Sun produces over its entire lifetime in the span of a few seconds—and this event is the brightest gamma ray burst,” said O’Connor.

This gamma-ray burst, known as GRB 221009A, was first spotted by telescopes including NASA’s Fermi Gamma-ray Space Telescope, Neil Gehrels Swift Observatory, and Wind spacecraft on Sunday morning Eastern time.