The Milky Way harbors a supermassive black hole called Sagittarius A* at its center, weighing about 4 million solar masses. It influences star orbits and the dynamics of the galactic core.
It matters because studying Sgr A* helps understand supermassive black holes in other galaxies.
It also informs our knowledge of galaxy formation and evolution.
The Milky Way’s central black hole contains millions of times the Sun’s mass.
[ESA, esa.int]