What is the name of the supermassive black hole at the center of the Milky Way?

The supermassive black hole at the center of the Milky Way is Sagittarius A*, often abbreviated Sgr A*.

Sagittarius A* lies about 26,000 light-years from Earth in the direction of the constellations Sagittarius and Scorpius. It has a mass of roughly 4.1 million Suns, yet its event-horizon region would fit within a space much smaller than the Solar System. Astronomers infer its presence from the rapid orbits of nearby stars, especially the star S2, whose path reveals an extremely massive, compact object.

The name can cause confusion because Sagittarius A is the larger radio source surrounding the Galactic Center. Sagittarius A* is the compact component associated with the black hole; the asterisk was added after astronomers identified an unusually compact radio source. The object was first detected as a strong radio source in 1974.

In 2022, the Event Horizon Telescope released the first image of Sagittarius A*. The image shows glowing material around the black hole's shadow, not the black hole itself, because light cannot escape from inside the event horizon.