Astronomers have discovered a pulsating dead star, emitting the energy of about 10 million suns, and believe it to be the biggest one ever found.
The dead star is the remnants of a supernova explosion and was discovered by Nasa's Nuclear Spectroscopic Telescope Array (NuSTAR).
It was previously thought the "pulsar", about 12 million light-years away from Earth in the Messier 82 galaxy, was a black hole but astronomers realised the discovery when picking up the pulses of x-rays coming out of the dead star.
"The pulsar appears to be eating the equivalent of a black hole diet," explained Fiona Harrison, the principal researcher. "This result will help us understand how black holes gorge and grow so quickly, which is an important event in the formation of galaxies and structures in the universe."