BUFFALO, N.Y. — The world was in awe last week when astronomers unveiled the first-ever picture of a black hole. Captured by a global network of ground-based telescopes, the image showed a dark abyss at the center of a glowing ring of super-heated gas.
University at Buffalo physicist Dejan Stojkovic, who was not involved in the research, said he was impressed by the detail of the image. He added that the ability to visualize a black hole heralds a new era of science in the field. A professor of physics in the UB College of Arts and Sciences, Stojkovic, PhD, has studied black holes as a theoretical physicist.
“This is the first time we have a visual image of the region so close to the black hole event horizon (a point of no return),” he said. “The event horizon is very sensitive to an underlying theoretical model. Right now the image is still consistent not only with what Einstein’s theory of general relativity predicts, but also with some exotic alternatives that differ from Einstein’s black holes only slightly. As this field progresses further, and images of higher and higher resolution become available, we will be able to distinguish between the different underlying theories.”
“In addition, the shape of the shadow that a black hole casts strongly depends on the black hole parameters like its mass and spin,” Stojkovic said. “This gives us a new and more direct way to estimate the black hole parameters.”
Black holes, predicted by physicist Karl Schwarzschild’s solution to Albert Einstein’s equations for gravity, are regions of space that are so dense that not even light can escape their gravity. The one that scientists imaged lies some 55 million light-years from Earth at the center of a galaxy called Messier 87 (M87).
More than 200 researchers from around the world worked together to capture the picture, a visual representation of radio data collected by a global network of telescopes known as the Event Horizon Telescope.
Though it was no secret that the international collaboration was working to image a black hole, the picture the scientists captured was surprisingly detailed, Stojkovic said. The result was an impressive scientific achievement, he said, and the effort was also aided by nature.
“We knew for some time that the Event Horizon Telescope would show the first-ever picture of a black hole, but the image was better than I expected,” Stojkovic said. “Nature was kind of generous to us, and the orientation of this black hole was such that we can clearly see a black disk at the center. It could have easily happened that the picture was much less clear and symmetric.”