The extragalactic explosion that sent light through the inner solar system last fall was 70 times brighter than any other eruption scientists have observed, researchers report.
Radiation from the explosion — a gamma-ray burst (GRB) known as GRB 221009A — hit Earth on October 9, 2022. It saturates the gamma-ray detectors of several space telescopes, earning it the nickname BOAT. all the time. ”
Astronomers continued to study BOAT in the months that followed using a variety of instruments to further characterize the explosion. And these efforts only added to the BOAT legend.
Eric Burns, an assistant professor of physics and astronomy at Louisiana State University, said at a press conference on Tuesday (March 28), “It’s just a huge burst. I’ve never seen it before,” he said. Meeting at the 20th Annual Conference of the High Energy Astrophysics Division of the American Astronomical Society in Hawaii.
“Boating is a once-in-10,000-year event,” Barnes added. “Therefore, it is quite possible that this is the brightest gamma-ray burst to hit Earth since human civilization began.”
brightest explosion ever
GRB is the most powerful explosion in the universe. They produce more energy in just a few seconds than Earth’s Sun produces over its entire 10 billion year lifespan.
Astronomers recognize two distinct classes. Short GRBs, about 2 seconds or less, and long GRBs lasting several minutes. Shorter variants were likely produced by collisions of ultra-dense stellar corpses known as neutron stars, astronomers say. Produced by a black hole born in
“So the core collapses. This creates a black hole, which powers a jet that propagates below the speed of light,” Burns said.
“When these jets go out, they release energy in the form of gamma-ray burst emissions,” he added. “This is followed by something called afterglow, after which the stored energy in the star causes a supernova explosion.”
BOAT was a long GRB, so researchers expect the supernova to appear about 1.9 billion light-years away from Earth. But despite searching the region with NASA’s James Webb Space Telescope, Hubble Space Telescope, and other instruments, it has yet to be found.
“It’s very faint if it’s there,” said Andrew Levan, an astrophysics professor at Radboud University in the Netherlands, in a NASA statement (opens in new tab). “We will continue to investigate, but it is possible that the entire star fell straight into the black hole instead of exploding.”
why is it so bright
GRB jets tend to be relatively narrow, so most of them don’t sweep over the Earth. However, although these astrophysical events are extreme, they are common enough to be observed in large numbers. The astronomer has so far cataloged about 12,000 of his GRBs using data collected by tools such as NASA’s Fermi Gamma-ray Space Telescope and Conus, a Russian instrument that flies on NASA’s wind probe. changed, Burns said.
He led an in-depth analysis of GRB’s records and established BOAT’s true brilliance. Other studies have also shown that this peak brightness is not due to overly powerful jets.
“If you compare the energies of this jet, it’s very similar to the energies of jets seen on other GRBs,” Kate Alexander, assistant professor of astronomy at the University of Arizona, said in a press conference Tuesday.
“Then why are you so bright?” she added. “It turned out that all the energy in this jet was concentrated in a very narrow angle. So every particle moving in this jet is a very narrow beam, and that narrow beam happens to hit the Earth. I was focused.”
She compared the effect to a garden hose. The BOAT’s jet is similar to the more intense spray obtained using a retracting nozzle.
Astronomers had to put some of the BOAT observations on hold months ago because the source region was behind the Sun from Earth’s perspective. But that area is now back in sight, and researchers are ready.
“More observations, including Hubble and Webb, are expected in the coming weeks and months,” Levan said during a teleconference on Tuesday.
He and many other researchers are particularly keen to determine whether the boat produced supernovae.
“Look at this space, hopefully for a more definitive answer!” Levan said.
The researchers reported these and other BOAT results in a special issue of The Astrophysical Journal Letters.
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