CAPE CANAVERAL (CBSMiami/AP) — Two incredibly massive black holes, the biggest ever observed, have been found by U.S. astronomers.
The black holes are the biggest known to exist, each one 10 billion times the size of our sun.
A team led by an astronomer at the University of California at Berkeley discovered the two gigantic black holes in clusters of galaxies 300 million light years away. That’s relatively close on the galactic scale.
The previous black hole record-holder is as large as 6 billion suns.
A black hole is formed by the collapse of a super-size star. It’s a region of space that has so much mass concentrated in it that there is no way for a nearby object to escape its gravitational pull, not even light can escape. The masses of black holes are measured by figuring out how strong their gravity is. More mass means more gravity and a stronger effect on stars that orbit in the galaxies that they inhabit. Using several telescopes, the scientists measured the speed of stars orbiting in these galaxies, thereby measuring the strength of the gravitational field of the black hole.
“Black holes inhabit the centres of nearly all galaxies − the centre of our very own Milky Way galaxy harbours a black hole four million times the mass of the sun − relatively speaking, a baby! But only a few dozens of these black holes have been ‘weighed’ carefully,” said Professor James Graham, director of the Dunlap Institute for Astronomy and Astrophysics at the University of Toronto.
The scientists say their findings suggest differences in the way black holes grow, depending on the size of the galaxy.
The research was released Monday by the journal Nature.
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