Astronomers making use of a phenomenon known as gravitational lensing have discovered a black hole about 33 billion times the mass of the Sun — close to the upper limit of how large scientists believe they can be.
The rare "ultramassive" black hole sits at the centre of Abell 1201, a supergiant elliptical galaxy residing in a galaxy cluster of the same name, about 2.7 billion light-years from Earth.
