The flare triggered numerous spacecraft and observatories around the world. By analyzing all this data, astronomers can now identify how bright it is and better understand its scientific impact.

“GRB 221009A was probably the brightest X-ray and gamma-ray burst since the dawn of human civilization,” said Eric Burns, professor of physics and astronomy at Louisiana State University in Baton Rouge. He analyzed about 7,000 gamma-ray bursts, mostly detected by NASA’s Fermi Space Gamma-ray Telescope and Russia’s Konus instrument aboard NASA’s Wind spacecraft, to determine how often such bright events might occur. Their answer: once every 10,000 years.

The flare was so bright that it effectively blinded most gamma-ray instruments in space, meaning they were unable to directly record the true intensity of the radiation. American scientists were able to reconstruct this information based on Fermi data. They then compared the results with those of a Russian team working on the Konus data, and those of Chinese teams analyzing observations from the GECAM-C detector on the SATech-01 satellites and instruments at the Insight-HXMT observatory. Together, they proved that the explosion was 70 times brighter than anything seen so far.

Burns and other scientists presented their new BOAT findings at the American Astronomical Society’s High Energy Astrophysics Division meeting in Waikoloa, Hawaii. Observations of the flare span the spectrum from radio waves to gamma rays and include data from numerous NASA missions and partners, 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 the main issue of The Astrophysical Journal Letters.

The signal from GRB 221009A was emitted about 1.9 billion years before it reached Earth, making it one of the closest known “long” GRBs with the initial or instantaneous emission lasting more than two seconds. Astronomers believe these flashes represent the birth cries of black holes, which are formed when the cores of massive stars collapse under their own weight. Rapidly absorbing the surrounding matter, the black hole shoots jets in opposite directions containing particles that have reached nearly the speed of light. These jets emit X-rays and gamma rays as they pierce the star and fly out into space.

Astronomers hope to find a brighter supernova in a few weeks with this type of GRB, but so far this has proven elusive. One reason is that the GRB occurs in a part of the sky just a few degrees above the plane of our own galaxy, where dense dust clouds can largely block incoming light.

“We can’t say with certainty that the flare was a supernova, which is surprising given its brightness,” said Andrew Levan, professor of astrophysics at Radboud University in Nijmegen, the Netherlands. As the dust clouds became more transparent in the infrared, Levan made observations in the near and mid-infrared with NASA’s James Webb Space Telescope — its first use for such research — and the Hubble Space Telescope to detect supernovae. “If it does, it’s very faint. “We plan to continue our search,” he added, “but it’s also possible that the entire star may have fallen into a black hole and not exploded.” Additional Webb and Hubble observations are planned in the next few months.

As the jets continue to expand into the material surrounding the doomed star, they create a multi-wavelength final flare that slowly fades away.

“This explosion was so close and so bright that it gave us an unprecedented opportunity to collect recent flare observations in the electromagnetic spectrum and test how well our models represent what’s really going on in jet emitters,” said Kate Alexander, associate professor of astronomy. at the University of Arizona in Tucson. “Twenty-five years of afterglow models that work so well can’t quite explain this jet,” she said. “In particular, we found a new radio component that we don’t fully understand. This could point to additional structure within the jet or suggest that we need to review our patterns of interaction of GRB jets with their environment.”

The sprinklers themselves weren’t very powerful, but they were extremely narrow—very much like the jet of a garden hose—and one was aimed directly at us, Alexander explained. The closer we look at the jet to our forehead, the brighter it will appear. Although the afterglow is unexpectedly radio dim, GRB 221009A is likely to remain visible for many years to come, providing a new opportunity to monitor the entire lifecycle of the powerful jet.

The flare also allowed astronomers to probe distant dust clouds in our galaxy. As the fast X-rays swept toward us, some bounced off layers of dust, creating an expanded “light echo” of the initial blast in the form of expanding X-ray rings from the blast field. The X-ray telescope at NASA’s Neil Gehrels Swift Observatory detected the presence of a series of echoes. A detailed observation using ESA’s (European Space Agency) XMM-Newton telescope and Swift’s data revealed that these extraordinary rings were created by 21 different dust clouds.

“How dust clouds scatter X-rays depends on the distance to them, the size of the dust particles, and the energy of the X-rays,” said Sergio Campana, head of research at the Brera Observatory and National Institute of Astrophysics in Merate. , Italy. “We were able to use the rings to reconstruct some of the rapid X-ray emission from the flare and determine where the dust clouds are in our galaxy.”

GRB 221009A is only the seventh gamma-ray burst to show X-ray rings, tripling the number previously observed in a nearby neighborhood. The echoes are caused by dust located 700 to 61,000 light-years away. The furthest echoes clear on the other side of our Milky Way galaxy were also 4,600 light-years above the center plane of the galaxy in which the Solar System is located.

Finally, the explosion provides an opportunity to explore the great cosmic question. “We think of black holes as all-consuming things, but do they also feed energy back into the universe?” asked Michela Negro, an astrophysicist at the University of Maryland, Baltimore County, and NASA’s Goddard Space Flight Center in Greenbelt.

His team was able to study the dust rings with NASA’s Imaging X-ray Polarimetry Explorer to see how the rapid emission is organized, which could provide insight into how jets form. Additionally, the small degree of polarization observed during the final flare phase confirms that we are looking at the jet almost from the front.

Along with similar measurements the team is currently working on using data from ESA’s INTEGRAL observatory, it’s possible to prove that SHIP’s jets are powered by taking advantage of the magnetic field energy powered by the black hole’s spin, the scientists say. Predictions based on such models have already successfully explained other aspects of this epidemic.