Astronomers have seen the most powerful flash of light they have ever seen in the sky. It was a gamma-ray burst, also the closest ever detected, at a distance of 2.4 billion light-years from Earth in the direction of the constellation Sagittarius. According to scientists, such a powerful flash of light could appear again in decades or even centuries.

The observation was made on October 14 with the ground-based international telescope Gemini South in Chile, operated by the US astronomical center NOIRLab, and was preceded by the first observations with X-ray and gamma-ray space telescopes on October 9. The record burst of light, called GRB221009A, is likely the result of a giant supernova explosion that spawned a black hole.

When black holes form, they create powerful “jets” of particles that accelerate to almost the speed of light. These jets then blast through the remnants of the now-destroyed star, causing powerful X-rays and gamma rays to blast through the universe. Such events in a few seconds release as much energy as the Sun will produce in its entire life of 10 billion years.

If their direction “points” to the Earth, then they can be seen as very bright flashes, which are called GRB (gamma-ray bursts). The first such electromagnetic bursts were accidentally detected by US military satellites in the 1960s.

A new titanic cosmic explosion mobilized astronomers around the world as they rushed to study the “meteorite” phenomenon. Significantly, the Chinese telescope has captured photons with an impressive energy of 18 teraelectronvolts (TeV), while CERN’s large accelerator produces particles with energies up to 13 TeV. A burst with an energy above 10 TeV has not yet been observed.

“The extraordinarily long-lived GRB221009A GRB is the brightest GRB ever recorded, and its afterglow breaks all records at all wavelengths. “Because it’s so bright and so close, we think it’s the ‘opportunity of the century’ to answer the most fundamental questions about these explosions,” said Brendan O’Connor of the University of Maryland.

The new record burst occurred 20 times closer to our planet than the average GRB burst to date, yet at a safe distance. But if such an explosion happened much closer to our planet, a few thousand light-years away, it could have catastrophic consequences and possibly cause a mass extinction of species (and humans). Some scientists, according to NASA, think it’s possible that at least one of Earth’s mass extinctions, the Ordovician about 450 million years ago, was caused by such a relatively nearby electromagnetic burst.

GRBs occur in two different forms. One, the rarest, has a short duration (up to two seconds), accounts for about 30% of all observed related phenomena, and is estimated to be caused by collisions of neutron stars (pulsars). The second type of gamma-ray bursts are longer (several minutes) and are probably caused by cataclysmic supernova explosions, which are 100 times brighter than supernovae and result from the death of massive stars. As in the last record event, astronomers can see “twilight” after such an explosion.

^{Source: RES-IPE}