A close up of a spiral galaxy with a black hole in the center

The secrets of ancient stars The title for the most massive black hole in our galaxy will always belong to Sagittarius A*, the supermassive black hole located at the center of the Milky Way, which has about 4 million times the mass of the sun, but that is because it’s a supermassive black hole, rather than a stellar black hole. The process by which supermassive black holes form is poorly understood, but one theory suggests it happens when massive cosmic clouds collapse. Stellar black holes form when massive stars die. So Gaia BH3 is the most massive black hole in our galaxy that formed from the death of a massive star. Stellar black holes observed across the Milky Way galaxy are about 10 times as massive as the sun on average. Until the discovery of Gaia BH3, the largest known stellar black hole in our galaxy was Cygnus X-1, which is 21 times the mass of the sun. While Gaia BH3 is an exceptional find within our galaxy by astronomers’ standards, it is similar in mass to objects found in very distant