Sagittarius A is a bright and very compact astronomical radio source at the center of the Milky Way, near the border of the constellations Sagittarius and Scorpius.
It is likely the location of a supermassive black hole, similar to those generally accepted to be at the centers of most if not all spiral and elliptical galaxies.
Astronomers have used NASA’s Chandra X-ray Observatory to take a major step in understanding why material around Sgr A* is extraordinarily faint in X-rays.
Sgr A* is one of very few black holes in the universe where we can actually witness the flow of matter nearby.