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Washington (AFP) – Astronomers have observed the brightest flash of light ever seen, from an event that happened 2.4 billion light-years from Earth and was likely triggered by the formation of a black hole.
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 monitored by scientists around the world.
Astrophysicist Brendan O’Connor told AFP that gamma-ray bursts that last hundreds of seconds, as happened on Sunday, would be caused by the death of massive stars, more than 30 times larger than ours. Sun.
The star explodes into a supernova, collapses into a black hole, then matter forms into a disk around the black hole, falls inside and is spewed out in a jet of energy that moves 99.99% of the speed of light.
The flash released photons carrying a record 18 teraelectronvolts of energy – that’s 18 with 12 zeros behind – and it impacted long-wave radio communications in Earth’s ionosphere.
“It’s really breaking records, both in terms of the amount of photons and the energy of the photons reaching us,” said O’Connor, who used infrared instruments on the Gemini South telescope in Chile to perform new sightings early Friday.
“Something this bright, this close, is truly a once-in-a-century event,” he added.
“Gamma-ray bursts typically release the same amount of energy that our Sun produces throughout its lifetime in a matter of seconds – and this event is the brightest gamma-ray burst.”
The gamma-ray burst, known as GRB 221009A, was first spotted by telescopes including NASA’s Fermi Gamma-ray Space Telescope, the Neil Gehrels Swift Observatory and the Wind spacecraft Sunday morning from the east.
1.9 billion year old movie
It originated from the direction of the constellation Sagitta and traveled about 1.9 billion years to reach Earth – less than the current distance from its starting point, as the universe is expanding.
Observing the event now is like watching a 1.9 billion year old record of these events unfold before us, giving astronomers a rare opportunity to glean new insights into things like the formation of black holes. .
“That’s what makes this kind of science so addicting — you get this adrenaline rush when these things happen,” said O’Connor, who is affiliated with the University of Maryland and George Washington University. .
He added that although the initial burst may have been visible to lucky amateur astronomers, it has since disappeared from view.
Over the next few weeks, he and others will continue to monitor supernova signatures at optical and infrared wavelengths, to confirm that their hypothesis about the origins of the flash is correct and that the event is consistent with known physics. .
Unfortunately, although the initial burst may have been visible to amateur astronomers, it has since faded.
Supernova explosions should also be responsible for producing heavy elements – such as gold, platinum, uranium – and astronomers will be looking for their signatures too.
Astrophysicists have written in the past that the power of gamma-ray bursts could cause extinction-level events here on Earth.
But O’Connor pointed out that because the energy jets are very tightly focused and unlikely to occur in our galaxy, this scenario is not something we should be concerned about.
© 2022 AFP