“We’re very excited to work on Sgr A*,” Daniel Marrone, an astrophysicist at the University of Arizona in Tucson, said in the Washington, D.C., news conference. Since the appearance of that black hole changes so quickly, the team is having to develop new techniques to analyze the data. The EHT team was able to collect some data on the Milky Way’s behemoth and are continuing to analyze that data, in the hopes of adding its image to the new black hole portrait gallery. Hopes are still high for a much-anticipated glimpse of Sgr A*. “It’s very significant it gives a glimpse of what the future might hold, but it doesn’t give us all the information that we want.” This first image is like the “shot heard round the world” that kicked off the American Revolutionary War, says Harvard University astrophysicist Avi Loeb who isn’t on the EHT team. “Just based on this ‘Does the black hole sit still and pose for me?’ point of view, we knew M87 would cooperate more.”Īfter more data analysis, the team hopes to solve some long-standing mysteries about black holes, such as how M87’s behemoth spews a bright jet of charged particles thousands of light-years into space. “During a single observation, Sgr A* doesn’t sit still, whereas M87 does,” says Özel, an astrophysicist at the University of Arizona in Tucson. How? We explain.ĭue to its gravitational oomph, gases swirling around M87’s black hole move and vary in brightness more slowly than they do around the Milky Way’s. The first real picture of the supermassive black hole at the center of galaxy M87. “The size in the sky is pretty darn similar,” says EHT team member Feryal Özel. That extra heft nearly balances out M87’s distance. But it’s also about 1,000 times as massive as the Milky Way’s giant, which weighs the equivalent of roughly 4 million suns. That black hole is 55 million light-years from Earth in the constellation Virgo, about 2,000 times as far as Sgr A*. But, it turns out, it was easier to image M87’s monster. “M87 is a monster even by supermassive black hole standards,” Markoff said.ĮHT trained its sights on both M87’s black hole and Sagittarius A*, the supermassive black hole at the center of the Milky Way. The team has also determined the behemoth’s size - its diameter stretches 38 billion kilometers - and that the black hole spins clockwise. But the new EHT measurements show that its mass is about 6.5 billion solar masses. Estimates made using different techniques have ranged between 3.5 billion and 7.22 billion times the mass of the sun. “Our mass determination by just directly looking at the shadow has helped resolve a longstanding controversy,” Sera Markoff, a theoretical astrophysicist at the University of Amsterdam, said in the Washington, D.C., news conference. The image also provides a new measurement of the black hole’s size and heft. Tiptoe any closer and you’d be inside the black hole - unable to report back on the results of any experiments. 16) near a black hole, but never at its edge. And that, of course, helps verify general relativity,” says physicist Clifford Will of the University of Florida in Gainesville who is not on the EHT team. “Being able to actually see this shadow and to detect it is a tremendous first step.”Įarlier studies have tested general relativity by looking at the motions of stars ( SN: 8/18/18, p. The picture is “one more strong piece of evidence supporting the existence of black holes. The image aligns with expectations of what a black hole should look like based on Einstein’s general theory of relativity, which predicts how spacetime is warped by the extreme mass of a black hole. “It really brings home how fortunate we are as a species at this particular time, with the capacity of the human mind to comprehend the universe, to have built all the science and technology to make it happen.” ( SN Online: 4/10/19) The much-anticipated big reveal of the image “lives up to the hype, that’s for sure,” says Yale University astrophysicist Priyamvada Natarajan, who is not on the EHT team. “It was just astonishment and wonder… to know that you’ve uncovered a part of the universe that was off limits to us.” “It’s been such a buildup,” Doeleman said. The EHT image reveals the shadow of M87’s black hole on its accretion disk. Appearing as a fuzzy, asymmetrical ring, it unveils for the first time a dark abyss of one of the universe’s most mysterious objects. But some black holes, especially supermassive ones dwelling in galaxies’ centers, stand out by voraciously accreting bright disks of gas and other material. Their gravity is so extreme that nothing, not even light, can escape across the boundary at a black hole’s edge, known as the event horizon. That’s because black holes are notoriously hard to see. All you need to know about the history of black holes.How scientists took the first picture of a black hole.
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