For the first time, astronomers have captured an image of the supermassive black hole at the center of our galaxy. It’s the first direct observation confirming the presence of the black hole, known as Sagittarius A*, as the beating heart of the Milky Way. This result provides overwhelming evidence that the object is indeed a black hole and yields valuable clues about the workings of sucs, which are thought to reside at the centre of most galaxies.
The image was produced by a global research team called the Event Horizon Telescope Collaboration, using observations from a worldwide network of radio telescopes including the University of Chicago-affiliated South Pole Telescope. “With the (Event Horizon Telescope or EHT) image, we have zoomed in a thousand times closer than these orbits, where the gravity grows a million times stronger. At this close range, the black hole accelerates matter to close to the speed of light and bends the paths of photons in the warped (space-time).”
The image is a long-anticipated look at the massive object that sits at the very center of our galaxy. Scientists had previously seen stars orbiting around something invisible, compact, and very massive at the center of the Milky Way. This strongly suggested that this object — known as Sagittarius A* — is a black hole, and today’s image provides the first direct visual evidence of it.
Although we cannot see the black hole itself, because it is completely dark, glowing gas around it reveals a telltale signature: a dark central region (called a “shadow”) surrounded by a bright ring-like structure. The new view captures light bent by the powerful gravity of the black hole, which is four million times more massive than our Sun.
“We were stunned by how well the size of the ring agreed with predictions from Einstein’s Theory of General Relativity,” said Event Horizon Telescope Project Scientist Geoffrey Bower from the Institute of Astronomy and Astrophysics, Academia Sinica, Taipei. “These unprecedented observations have greatly improved our understanding of what happens at the very center of our galaxy, and offer new insights on how these giant black holes interact with their surroundings.”
“For decades, astronomers have wondered what lies at the heart of our galaxy, pulling stars into tight orbits through its immense gravity,” Michael Johnson, astrophysicist at the Center for Astrophysics | Harvard & Smithsonian, said in a statement.
The black hole is about 27,000 light-years away from Earth. Our solar system is located in one of the spiral arms of the Milky Way galaxy, which is why we’re so distant from the galactic center. If we could see this in our night sky, the black hole would appear to be the same size as a doughnut sitting on the moon.
The results are published May 12 in a special issue of The Astrophysical Journal Letters.
—
Photo Credit: JohaPlay / Shutterstock.com