A truly enormous black hole been discovered in the constellation Cetus with a mass equivalent to 40 billion times that of our sun. Put another way, this black hole is so enormous that its mass is equal to around that of two-thirds of all the stars found within our Milky Way galaxy.
Almost Size of our Solar System
Furthermore, the size of the supermassive black hole is so big that its event horizon (Schwarzschild radius) would be huge enough to engulf all the orbits of the planets in our solar system, as well as easily stretching past Pluto (39.5 AU).
In fact, the black hole’s event horizon is calculated to be an incredible 790 AU in diameter, with one astronomical unit equivalent to the distance between the Earth and the Sun (92,955,807 miles/ 149,597,871 km). In comparison, the black hole’s event horizon would therefore extend far past the Kuiper Belt (50 AU), and the heliopause (123 AU), and even approach close to the start of the Oort Cloud (1000 AU).
700 Million Light-Years Distant
The gargantuan black hole sits at the center of a supergiant elliptical galaxy called Holmberg 15A, which in turn is situated in the middle of a cluster of galaxies called Abell 85.
Thankfully, however, this truly massive black hole is found around 700 million light-years away, putting it a safe distance away from any Earthly concerns.
Origins of the Supermassive Black Hole
According to scientists, the supermassive black hole (SMBH) likely formed after two huge cored elliptical galaxies merged. During the merger, the two galaxies’ respective central black holes would have also merged.
In a process called “core scouring”, the gravitational interactions between the two galaxies would have also resulted in the black holes sling-shooting stars and gas away from the center of the remnant galaxy. With little gas remaining in the core, no new stars can form, and as Roberto Saglia, senior scientist at the Max Planck Institute for Extraterrestrial Physics (MPE) and lecturer at the Ludwig Maximilians University (LMU), explains:
“Even though the central galaxy of the cluster Abell 85 has the enormous visible mass of about 2 trillion (1012) solar masses in stars, the center of the galaxy is extremely diffuse and faint. This is why a joint group of astronomers at MPE and the University Observatory Munich got interested in the galaxy. This central diffuse region in the galaxy is almost as large as the Large Magellanic Cloud, and this was a suspicious clue for the presence of a black hole with a very high mass.”