Photo: Science Image Library – MEHAU KULYK via Getty Images
Scientists have detected an “unprecedented” explosion of energy in space, known as a gamma ray burst (GRB), which appears brighter at some wavelengths than any such event observed so far.
Gamma ray bursts are massive explosions fueled by intense cosmic phenomena, such as the death of massive stars, and produce some of the brightest scenes in the universe. News of this particular explosion started spreading across social media after it was detected on Sunday by the Fermi Gamma Ray Space Telescope and Neil Gerels Swift Observatory, both NASA missions, with some astronomers describing it as “extraordinary event“Maybe”The brightest GRB ever. “
Phil Evans, an astronomer at the University of Leicester working on the Swift X-ray Telescope described the explosion, known as GRB 221009A, as “really stupidly bright” at Monday Tweet.
In an email to Motherboard, Evans emphasized that the discovery is so recent that it will take some time to decipher its significance, but noted that the eruption “is clearly the brightest GRB we’ve seen in X-rays, at least in the time after the initial explosion that we observed” .
“The new GRB 221009A is about 1,000 times brighter than the typical GRB and a few hundred times brighter than the brightest one seen before – but that’s only true in X-rays,” Evans said. “In gamma rays it is one of the brightest visible (according to a report by the Fermi telescope team).”
Marcos Santander, an astronomer at the University of Alabama, noted in an email that Fermi’s Gamma Ray Burst Monitor (GBM) was the first to detect the event, and immediately declared it exceptional.
“GBM is the most prolific GRB detector and on average detects GRBs nearly every day, and has collected thousands of GRBs in over 14 years of operation since Fermi launched in 2008,” Santander told Motherboard. “Of those thousands, October 9 was by far the brightest”—so bright, in fact, that it “blind the machines a bit given the number of gamma rays that were arriving in a very short period of time.”
“GRBs are also the brightest events in the universe,” he continued. “This could intrinsically have a brightness of 10^22 times the brightness of the Sun, or about a trillion times the total energy output of all the stars in the Milky Way combined during that short period that the GRB was on if I really had the numbers.”
Perhaps the show of cosmic light indicates the active death of a massive star and its subsequent transformation into a black hole. It is unparalleled at some wavelengths in part because it occurred about 2 billion light-years from Earth. This is an objectively large distance, but it is relatively close to the GRB.
“Keep in mind, of course, that this is a very new event, and it will take some time before we get the full picture, so this is somewhat preliminary,” Evans said. “However…it appears to be a ‘long GRB’, and this is fairly well understood. What happens is that a very massive, rapidly rotating star reaches the point where its nuclear reactions are no longer able to produce enough energy to support the star’s weight. Its center collapses and forms A new black hole, and that releases a lot of energy.”
He continued, “This causes some of the star-forming material to be released in narrow ‘jet’ from above and below the star, which are jets of material moving nearly at the speed of light.” “If one of these planes is pointed at Earth, we see the GRB. So that’s what happened here. Why it’s so bright compared to the others isn’t clear yet” although “part of it is just that it’s close.”
Swift, which has been orbiting Earth since 2004, did not detect the initial eruption of GRB 221009A because our planet was blocking that part of the sky. But the observatory’s Burst Alert Telescope (BAT) picked up the remarkable aftermath of the eruption about an hour later, when its aftermath emerged.
“This is quite unprecedented – the explosion itself only lasted about 5 minutes (which is fairly typical for a GRB), but GRB explosions are followed by a ‘later aurora’ that usually fades relatively quickly,” Evans said. “We’ve never had a GRB where the subsequent aurora was so bright that it fired BAT.”
The GRB does not appear to be very bright at optical wavelengths, but this may be a result of its location in the sky as well as the lack of immediate observations using optical instruments.
“Because of where the GRB is, we have to look directly through the disk of our galaxy to see it,” Evans said. “This disc absorbs *a lot* of optical light, so if it was in a ‘better’ part of the sky it would have been brighter.”
“The other thing is that, as far as I know, no one noticed it with an optical telescope until after Swift detected it, so 55 minutes after the GRB (that’s because Fermi doesn’t give very good positions for where the GRB is; Swift does). If people had noticed it, then it’s not. When it first happened, I wouldn’t be personally surprised if it broke all visual records… but since they didn’t, we can’t say that it happened.”
Given its impressive luminosity and potentially mind-boggling potential, Evans and several other scientists will watch the evolution of GRB 221009A as it fades into lower-energy light forms.
“I think the first step is to put together all the data collected by all the instruments that spotted the explosion and start looking at the details of how this event actually happened,” Santander said. “These are, after all, the most energetic eruptions in the universe, so you want to understand what kind of object could produce such an event, what drove this intense emission, what kinds of particles are being accelerated and so on.”
“Not only that, being so far away, GRBs can be used as probes to study the intervening properties of space, from the amount of light left over from previous generations of stars, to studying dust clouds in our galaxy and even basic physics tests.” “There will be many papers written about this batch, and the first step is to compile all the information and the different observatories that provide different perspectives so that there is more information when the analyzes are done and published.”
All of this new research will help explain why this distant black hole produces such blinding cosmic fireworks, a question that could open a window into the universe’s most energetic phenomena.
“The underlying science here is that we’re looking at really extreme physics – very strong gravity, big masses that move very fast while very hot – conditions that you could never create in a lab, so the only way we can begin to understand that is by studying Extreme astronomical objects such as GRBs,” concluded Evans. “A lot of the open questions are very detailed physics (and I don’t pretend to understand all of them!), especially about what’s going on inside those jets – how particles are accelerated, interacted, radiated energy, etc. And because this event is so bright, it’s really a dataset Brilliant way to explore those physics.”