New class of black hole discovered

U.S. astronomers said they have found what appears to be the first black hole in the moderate size range.

A team at the University of Michigan using NASA's orbiting Chandra X-ray Observatory said they discovered peculiar X-ray outbursts coming from a black hole in the galaxy M74, about 32 million light-years from Earth in the constellation Pisces.

Most known black holes are either about 10 times more massive than the sun -- indicating they are the remnants of giant stars that exploded as supernovae -- or up to billions of solar masses, which exist at the centers of most galaxies, including the Milky Way.

The new object emits more powerful X-ray emissions than would any sun-sized black hole or neutron star, and the emissions spike about every two hours. Both characteristics make the object a primary candidate to be an intermediate-sized black hole, with a mass of about 10,000 suns, they said, something that up to now has existed only in computer simulations.

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