A black hole is a region of space — time, the gravitational pull is so great that it can not leave even objects moving at the speed of light, including photons of light.
The boundary of this region (the point of no return) is called the event horizon, and its characteristic size is the gravitational radius.
April 10, 2019, the General public was shown the first ever photograph of a black hole.
A black hole is a gigantic sphere.
The photo of the bright yellow-orange color shows the boundary of the event horizon, which is a ring of hot gas.
The “supermassive” black hole is located at a distance of 54 million light years from Earth in the center of the galaxy called Messier 87, or M87. By mass it is equal to 6,5 billion suns, and its width is 38 billion kilometers.
Note: © Photo Event Horizon Telescope Collaboration