On Thursday, astronomers unveiled the first clear visual evidence of a black hole at the heart of the Milky Way. The latest image is the second ever to be taken.
The “gentle giant” reveals an oval-shaped emptiness in the center of our galaxy’s core, which scientists have dubbed Sagittarius A*, encircled by dazzling rings of burning gas.
Michael Johnson of the Harvard-Smithsonian Center for Astrophysics said to NBC News, “For decades, astronomers have wondered what lies at the center of our galaxy, pulling stars into tight orbits through its massive gravity.”
Astronomers from 80 various institutions worldwide, identified as the Event Horizon Telescope (EHT), collaborated to carry out the research. The findings are in a special edition of The Astrophysical Journal Letters.
There are approximately 27,000 light-years between Sagittarius A* and Earth, and it has a mass 4 million times greater than our sun. It is widely believed that nearly all galaxies include a black hole at their core, but because these massive objects do not emit light, astronomers have difficulty observing them.
An astronomer who was part of this research team said the photo of Sagittarius A* shows the black hole’s telltale shadow, which is unviewable due to the star’s dense cloud of gas.
Observations demonstrate how black holes “feed” by ingesting surrounding gas and bending light. The bright ring is the light emitted by the hot gas spinning around the black hole. When the light gets too close to a black hole, it gets swallowed up and leaves behind only the black hole’s center.
“The black hole is attracting a lot of gas to it. Its gravitational pull is so strong that the matter around it can’t resist. But it’s pulling it into an extremely tiny space. … Imagine sucking an elephant through a straw,” stated Sheperd Doeleman, an astronomer at the Harvard-Smithsonian Center for Astrophysics and founding director of the Event Horizon Telescope, per The Washington Post.
It took eight radio telescopes to create “a planet-sized telescope” that could capture the image of the black hole. Researchers at the Haystack Observatory of Massachusetts linked “two telescopes that are quite far apart,” according to Vincent Fish, a scientist researcher at MIT in Massachusetts.
Scientists could view Sagittarius A* from various distances and angles, which provided crucial information to make a cohesive picture.
According to Katie Bouman, an associate professor of computing and mathematical science at the California Institute of Technology, the process was like listening to a tune played on a piano with a bunch of missing notes.
“Since we don’t know when the missing keys should be hit, there’s an endless number of possible tunes that could be playing,” she said. “Nonetheless, with enough functioning keys, our brains can often fill in the gaps to recognize the song correctly.”
As a result of the Event Horizon Telescope’s observations, scientists may better understand how supermassive black holes emerge and expand to their considerable dimensions.
When the same scientists released an image of a black hole earlier this year, they dubbed it M87*. This supermassive black hole is 53 million light-years away in the Messier 87 galaxy.
Researchers said that despite Sagittarius A* having a lower mass and smaller size than Messier 87’s black hole, the two black holes appear identical.
Bouman described the discovery of what resides at the center of our galaxy as “amazing.”
“I mean, what’s more, cooler than seeing the black hole at the center of our Milky Way?” he asked.
