The discovery could help to unravel the evolution of the Universe’s most extreme environments.

Astronomers say they have spied a black hole with a mass around 50,000 times that of the Sun, providing the best evidence yet that black holes of this size exist.

Stellar-mass black holes have masses up to 100 times the Sun’s mass, and supermassive black holes weigh in at millions of solar masses. But black holes in between these extremes have proved hard to spot, in part because they suck in matter less vigorously than their supermassive cousins.

Dacheng Lin at the University of New Hampshire in Durham and his colleagues studied a potential intermediate-mass black hole roughly 247 million parsecs away. Using the XMM-Newton satellite, they confirmed that X-rays from the source match the glow expected from a star being pulled apart by a black hole with a mass of 50,000 Suns. Images from the Hubble Space Telescope ruled out an alternative explanation: that the X-rays could come from a neutron star in the Milky Way.

The observations make the source one of the strongest candidates for an intermediate-mass black hole, whose existence could help to explain how others grow to a supermassive size.