On October 9, an unusually bright and persistent pulse of high-energy radiation overtook the Earth, attracting the attention of astronomers around the world.The intense radiation comes from gamma-ray bursts – the most powerful class of explosions in the universe – which are among the most dazzling events known.
A week ago, on Sunday morning EST, a wave of X-rays and gamma rays passed through the solar system. It has activated detectors on NASA’s Fermi Gamma-ray space telescope, the Neil Gales-Swift Observatory, and the Wind spacecraft, among other devices. All over the world, telescopes have turned to the site to study its consequences and new observations continue.
The explosion, known as GRB 221009A, provided an unexpectedly exciting start to the 10th Fermi Symposium, a gathering of gamma-ray astronomers in Johannesburg, South Africa. “Suffice it to say that the meeting really started with a bang – everyone talked about it,” said Judy Racusin, a scientist with the Fermi Associate Project at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, who attended the match. . “
The signal originates in the direction of the Sagitta constellation and is estimated to have taken 1.9 billion years to reach Earth. Many astronomers believe it represents the birth cries of a new black hole that formed in the center of a massive star and collapsed under its own weight. In this case, a developing black hole fires a powerful jet of particles that travel at almost the speed of light. These high-energy jets penetrate the star, emitting X-rays and gamma rays as they travel through space.
The explosion also provided a long-awaited look at two experiments aboard the International Space Station (ISS): NASA’s NICER X-ray telescope and a detector in Japan called MAXI (All-weather X-ray Image Monitor). . Launched in April, the connection is known as the Orbital High Energy Monitoring Alert Network (OHMAN). It allows NICER to quickly address outbreaks detected by the MAXI, actions that previously required the intervention of scientists in the field.
Zaven Arzoumanian, chief scientific officer of NICER at Goddard, said: “OHMAN provides an automatic alert that allows NICER to follow up within three hours, provided the telescope is able to see the source. Future opportunities may arise. lead to a response time of several minutes. “.
The light from this ancient explosion has brought valuable new information about the collapse of stars, the birth of black holes, the behavior and interactions of matter near the speed of light, conditions in distant galaxies, and more. Astronomers may not detect such bright GRBs again for decades.
According to a preliminary analysis, Fermi’s Large Area Telescope (LAT) detected the explosion for more than 10 hours. One of the reasons for the particular brightness and duration of this burst is that, like GRB, it is relatively close to us.
Roberta Pillera, a PhD student at Politecnico di Bari in Italy, said: “This burst is much closer than a typical GRB, which is exciting because it allows us to detect many details that would otherwise be too faint to see. But it is also one of the brightest and most energetic explosions ever seen, regardless of distance, which makes it doubly exciting. “
