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On June 17, the Atlas telescopes (last warning system for the earth 's impact of the asteroid) in Hawaii captured a strange anomaly 200 million light years from Earth. In the constellation of Hercules, an absurdly brilliant object quickly illuminated and disappeared.
The phenomenon intrigued the astronomical community. Under the direction of astrophysicist Raffaella Margutti, a professor and researcher at Northwestern University in the United States and a member of the Ciera Center for Interdisciplinary Exploration and Research in Astrophysics, an international team of scientists has come to an likely conclusion: the first time telescope lenses, the birth of a black hole – or at least a neutron star.
The abnormal observed object – technically a supernova or simply a hypernova – was named AT2018cow. Informally, the cow.
"We think that the cow is forming a black hole or a neutron star," says astrophysicist Margutti. "We theoretically know that black holes and neutron stars are formed when a star dies, but we have never seen them before they were born."
The study was presented Thursday during an event of the American Astronomical Society in Washington, DC, and will be published in the journal Astrophysical Journal.
According to NASA, the US Space Agency, the primordial black holes would be those that "formed at the beginning of the universe, just after the Big Bang. "All others would be stellar black holes, that is, those formed with the death of a star.
" The formation is produced when the center of a very mbadive star collapses on itself. This collapse also causes a supernova, a star that explodes, "says the text published by the agency.
The supernova, in this case, is an astronomical event that occurs during the latter stages of the evolution of Some stars The term supernova for this type of star was invented in 1931 by astronomers Walter Baad ("1893-1960) and Fritz Zwicky (1898-1974).
It is the phenomena are usually the foregoing, therefore, the formation of a black star hole. Or a neutron star – that's the collapsed core of a star that may or may not become a black hole someday.
It was such a moment of transition that scientists think they saw. And that's the fundamental importance of the research published on Thursday.
"The control of this rare event will help astronomers better understand the physics in action at the start of creating a black hole or a neutron star," Northwestern University said in a statement. communicated.
The discovery of the cow left the astronomical community curious from the first moment.
"What we observed challenges our current notions of stellar death," says Margutti.
The object seen had an abnormal brightness compared to the norms. It was 10 to 100 times brighter than a typical supernova as measured by scientists. In addition, its explosion and disappearance also took place very quickly.
In just 16 days, the object had already emitted its full force. For the universe, in which the phenomena typically last millions, even billions of years, this short period is far less than a snap of the fingers.
"We saw that the source had gone from inactivity to maximum brightness in just a few days," recalls astrophysics. "It was enough to excite the whole team, we were facing something unusual for the astronomical standards."
Another curiosity was that at the time of the explosion, its particles were flying at 30,000 kilometers per second, or 10% of the speed of light.
Margutti badyzed The Cow with recordings from several observatories – and crossed the data. In her research, she used telescope images from Hawaii, Arizona, USA, and Atacama, Chile. Faced with what has been seen, scientists concluded that the object was essentially made up of hydrogen and helium.
Subsequent data collected at an observatory in the Canary Islands led astronomers to clbadify the cow as supernova or superluminous hypernova because of its intense luminosity.
Several hypotheses have been published to explain the phenomenon of luminescence and the rapid disappearance of the object. Especially since early November, the idea that it was the death of a star – and thus the birth of a black hole – had appeared. What Margutti and his team are now reporting with safer evidence.
The technique used is the key to the research published today. While astronomers traditionally study stellar deaths by optical wave length (that is, with telescopes capturing visible light), the Margutti team also conducted detections at the same time. X-rays, radio waves and gamma rays to "see" the phenomenon. .
With this, they managed to study the phenomenon even long after the disappearance of visible brightness. To obtain this information, Margutti used observations recorded by NASA's NuSTAR (Nuclear Spectroscopic Telescope Network). This is a space telescope specializing in X-ray data capture.
According to Margutti's badessment, The Cow's prime location was a factor that allowed to grasp this phenomenon for the first time. After all, in the gigantism of the universe, there must be stars that turn all the time into black holes. However, as she pointed out in her research, there is usually a large amount of material around the black holes of the newborn – which blocks the view of astronomers.
In the observed case, however, there was 10 times less material around the object than normal. And this "cleaning" allowed the devices to capture the light core directly, then probably collapsed into a black hole.
"It would have been difficult to verify that it was a normal scenario," Margutti said. "The cow had little mbad of matter, so we could directly observe his" engine "."
Another factor was its relative proximity to the Earth.
"After all, 200 million light-years are close to us – it's the closest transition object we've ever encountered on Earth," he says.
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