That famous black hole gets a second look

Hello darkness, our old friend, we come to stare at you again.

At the center of Messier 87, a giant galaxy 55 million light-years from Earth, lies a darkness 25 billion miles across and the size of 6.5 billion suns — a trapdoor to infinity called a black hole.

In 2017, a group of astronomers operating the Event Horizon Telescope, a global network of radio telescopes, produced an image of the black hole in Messier 87, or M87, the first ever image of a black hole. It revealed a fiery, slightly crooked donut of hot gas circling a dark void, like water circling a drain, just as Albert Einstein's general theory of relativity had predicted in 1915. When the resulting photo was unveiled in 2019, it made the front page of news outlets around the world. It is now in the collection of the Museum of Modern Art in New York.

The same team of scientists did it again, this time even better. In 2018, a year after the first image was captured, astronomers again gazed into the darkness of M87 with a slightly enlarged network that provided higher resolution. The result, published last week in the journal Astronomy and Astrophysicsshows the same lumpy donut and central hole in even more appetizing detail, suggesting the astronomers got things right the first time.

“The first image of a black hole was so similar to the mathematical predictions that it almost seemed like a fluke,” says Dominic Chang, a physicist Ph.D. candidate at Harvard who works on the Event Horizon team, said in a press release published by the Center for Astrophysics/Harvard & Smithsonian in Cambridge, Massachusetts, where the project is based.

“Having the opportunity to perform new tests using new data, with a new telescope and seeing the same structure is a crucial confirmation of our main conclusions,” he said.

There was one change in the ring around M87's black hole. The brightest lump had shifted about 30 degrees counterclockwise around the ring from where it had been a year earlier. The astronomers said they predicted the hotspot would move.

“While general relativity says that the ring size should remain fairly fixed, the emission from the turbulent, messy accretion disk around the black hole will cause the brightest part of the ring to wobble around a common center,” said Britt Jeter, a postdoctoral researcher at the Academia. Sinica Institute for Astronomy and Astrophysics in Taiwan, the press release said. “The amount of fluctuation we see over time is something we can use to test our theories about the magnetic field and plasma environment around the black hole.”