The supermassive black hole Sagittarius A* at the Galactic Center.Sagittarius A* (Sgr A*) is the supermassive black hole at the center of our Milky Way galaxy. With a mass about four million times that of the Sun, it anchors the orbits of stars in the galactic core. While it is relatively quiet compared to black holes in other galaxies, it occasionally flares in X-rays and infrared, and its gravitational influence shapes the motion of gas and stars in the central region.
The existence of a massive compact object at the galactic center was proposed in the 1970s, and the name Sagittarius A* was coined in 1982. The Nobel Prize in Physics 2020 was awarded for the discovery that Sgr A* is a supermassive black hole.
Sgr A* is so massive that its gravity dominates a region of space about the size of our solar system. Stars orbiting it, like the famous star S2, follow paths that can be precisely measured to test Einstein's theory of general relativity. The black hole itself is invisible, but its presence is revealed by the motion of these stars and by the radiation emitted from gas that heats up as it spirals inward.
Sgr A* serves as a natural laboratory for testing general relativity in a strong gravitational field and for studying how supermassive black holes grow and interact with their host galaxies.
If you were to stand at the event horizon of Sgr A*, you would experience tidal forces so strong that you would be stretched into a thin stream of atoms, a process astronomers call 'spaghettification'.





















