’Mighty Mouse’ of stellar remnants

An international team of astronomers has found a pulsating, dead star beaming with the energy of about 10 million suns. This is the brightest pulsar - a dense stellar remnant left over from a supernova explosion - ever recorded. The true nature of ULXs has remained hidden since their discovery about 20 years ago - Andy Fabian "You might think of this pulsar as the 'Mighty Mouse' of stellar remnants," said Fiona Harrison of the California Institute of Technology. "It has all the power of a black hole but with much less mass." The discovery, made with NASA's Nuclear Spectroscopic Telescope Array (NuSTAR), is helping astronomers better understand mysterious sources of fierce X-rays, called ultraluminous X-ray sources, or ULXs. Before now, all ULXs were thought to be black holes. New data from NuSTAR show that at least one ULX, about 12 million light-years away in the galaxy Messier 82 (M82), is actually a pulsar. "The pulsar appears to be eating the equivalent of a black hole diet," said Harrison, NuSTAR principal investigator.