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Space scientists reveal brightest gamma explosion ever

cientists have revealed how Nasa satellites detected the brightest ever gamma ray explosion in space.
The gamma-ray burst (GRB) occurred two billion lightyears from Earth and illuminated much of the galaxy.
Images of the rare and powerful cosmic phenomenon show a halo and "bullseye" like shapes.
Experts, including academics from the University of Leicester, say the GRB was ten times brighter than any other previously detected.
They have released detailed analysis of the powerful explosion, which happened on 9 October, 2022.
The blast was officially named GRB 221009A but has been nicknamed the BOAT - Brightest Of All Time - by those working on a mission Nasa calls Swift.

X-ray astronomer Dr Phil Evans, who leads the University of Leicester's involvement in Swift, said: "We were really lucky to see something like this. We estimate that events this bright occur roughly once every thousand years.
"By studying the evolution of this astonishingly bright GRB in great detail, we can learn a lot about the physics of a blast wave.
"Just like slow-mo cameras reveal details about movement, breaking our data into small time pieces allows us to see how the GRB changes and learn more."
The Swift team said its Neil Gehrels Swift Observatory, a satellite telescope designed to study GRBs from space, was initially unable to observe the burst because the Earth was obstructing its view.
However 55 minutes later, when the satellite's orbit allowed it to have a clear view of the GRB, its systems successfully detected it and created images of it.

Dr Andy Beadmore, who is also part of the Swift team at the University of Leicester, said: "These patterns are not just beautiful but are also useful scientifically.
"We're seeing a significant amount of dust in our galaxy being lit up by the intense burst of light from the GRB - two billion lightyears away - like a torch shining through a cloud.
"This lets us study its nature and composition, which was found to extend to large distances from the Sun.
"The brightness of this GRB means that we can collect much better data than normal, and so move beyond simple models of the GRB physics that we normally use - they just can't explain these data."

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https://www.bbc.com/news/uk-england-leic...ign=Social_Flow

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On Sunday, Oct. 9, 2022, a pulse of intense radiation swept through the solar system so exceptional that astronomers quickly dubbed it the BOAT – the brightest of all time.
The source was a gamma-ray burst (GRB), the most powerful class of explosions in the universe

The burst triggered detectors on numerous spacecraft, and observatories around the globe followed up. After combing through all of this data, astronomers can now characterize just how bright it was and better understand its scientific impact.

“GRB 221009A was likely the brightest burst at X-ray and gamma-ray energies to occur since human civilization began,” said Eric Burns, an assistant professor of physics and astronomy at Louisiana State University in Baton Rouge. He led an analysis of some 7,000 GRBs – mostly detected by NASA’s Fermi Gamma-ray Space Telescope and the Russian Konus instrument on NASA’s Wind spacecraft – to establish how frequently events this bright may occur. Their answer: once in every 10,000 years.

The burst was so bright it effectively blinded most gamma-ray instruments in space, which means they could not directly record the real intensity of the emission. U.S. scientists were able to reconstruct this information from the Fermi data. They then compared the results with those from the Russian team working on Konus data and Chinese teams analyzing observations from the GECAM-C detector on their SATech-01 satellite and instruments on their Insight-HXMT observatory. Together, they prove the burst was 70 times brighter than any yet seen.

Burns and other scientists presented new findings about the BOAT at the High Energy Astrophysics Division meeting of the American Astronomical Society in Waikoloa, Hawaii. Observations of the burst span the spectrum, from radio waves to gamma rays, and include data from many NASA and partner missions, including the NICER X-ray telescope on the International Space Station, NASA’s NuSTAR observatory, and even Voyager 1 in interstellar space. Papers describing the results presented appear in a focus issue of The Astrophysical Journal Letters.

The signal from GRB 221009A had been traveling for about 1.9 billion years before it reached Earth, making it among the closest-known “long” GRBs, whose initial, or prompt, emission lasts more than two seconds. Astronomers think these bursts represent the birth cries of black holes formed when the cores of massive stars collapse under their own weight. As it quickly ingests the surrounding matter, the black hole blasts out jets in opposite directions containing particles accelerated to near the speed of light. These jets pierce through the star, emitting X-rays and gamma rays as they stream into space.

With this type of GRB, astronomers expect to find a brightening supernova a few weeks later, but so far it has proven elusive. One reason is that the GRB appeared in a part of the sky that’s just a few degrees above the plane of our own galaxy, where thick dust clouds can greatly dim incoming light.

“We cannot say conclusively that there is a supernova, which is surprising given the burst’s brightness,” said Andrew Levan, a professor of astrophysics at Radboud University in Nijmegen, Netherlands. Since dust clouds become more transparent at infrared wavelengths, Levan led near- and mid-infrared observations using NASA’s James Webb Space Telescope – its first use for this kind of study – as well as the Hubble Space Telescope to spot the supernova. “If it’s there, it’s very faint. We plan to keep looking,” he added, “but it’s possible the entire star collapsed straight into the black hole instead of exploding.” Additional Webb and Hubble observations are planned over the next few months.

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https://www.nasa.gov/feature/goddard/202...gamma-ray-burst