Astronomers have discovered a black hole with a mass of approximately 36 billion suns. It ranks among the ten most massive objects ever discovered and may be the largest black hole. It is located approximately 5 billion light-years from Earth.
This object is a "dormant" black hole: it does not emit the intense energy flux of active quasars, making it difficult to detect. By comparison, the black hole at the center of the Milky Way has a mass of only 4.15 million suns.
The measurement was made possible by gravitational lensing, an effect predicted by Albert Einstein in which light from a distant object is bent by the strong force of gravity. In the case of the cosmic horseshoe, light from background galaxies is distorted by the black hole's parent galaxy, forming a nearly perfect horseshoe-shaped "Einstein ring."
According to Carlos Melo, who led the study, this method opens the way to detecting "hidden" supermassive black holes throughout the universe, even though they are extremely difficult to detect. Scientists have proposed a new theory: according to it, as galaxies grow, matter flows into their centers, feeding black holes, and the energy from quasars can prevent the formation of new stars.
