What’s a black hole?
First of all, black holes are collapsed stars with gravity so strong that even light cannot escape their grasp. One of the black holes we’re expecting to get a glimpse of this week – known as Sagittarius A – is the “supermassive” one that’s at the center of our Milky Way galaxy.
Supermassive black holes are millions to billions times more massive than our sun, and appear to be in the center of almost all galaxies, the National Science Foundationsaid.
Astronomers this week are also expected to release images of another supermassive black hole, one that’s 53.5 million light-years away.