What's the most massive black hole we know of?
TON 618 is often cited, but the central supermassive black hole of the Phoenix Cluster (Phoenix A) is potentially the most massive black hole in the observable universe. Scientists use a unit of measurement called a Solar Mass to compare the mass of the black hole with our sun. A Solar Mass is approximately equivalent to the mass of our Sun. The models of the scale of the supermassive black hole in the center of the Phoenix Cluster suggested by the scientists paper indicate an estimated mass on the order of 100 billion Solar Masses. That’s 24,100 times the mass of the black hole at the center of the Milky Way (Sagittarius A*). This supermassive black hole has a size of approximately 2,000 astronomical units (1 AU = The distance between the Sun and Earth). That’s a size comparable to 50 times the distance from the Sun to Pluto (or if placed where the Sun is it could reach the inner limit of the Oort Cloud). That would make it have a circumference that would take 71 days and 14 hours to travel at light speed (c = 299,792,458 meters per second).
