Astronomers recently spotted the two biggest
black holes ever seen in the universe."For comparison, these black holes are
2,500 times as massive as the black hole at the center of the Milky Way galaxy,
whose event horizon is one-fifth the orbit of Mercury".
According to Space.com : The scientists used
the Gemini and Keck observatories in Hawaii and the McDonald Observatory in
Texas to monitor the velocities of stars orbiting around the centers of a pair
of galaxies. These velocities reveal the strength of the gravitational pull on
those stars, which in turn is linked with the masses of the black holes lurking
there.
Study co-author Nicholas
McConnell, a graduate student at the University of California, Berkeley, told
Space.com. His team's findings will be published in the journal Nature on Dec.
8. One black hole is located in the galaxy NGC 3842, around 320 million light
years from Earth; it has a mass about 9.7 billion times the mass of our Sun,the
Guardian reported. The second black hole is about 336 million light years from
Earth, located at the center of the galaxy NGC 4889; it has a mass of about 21
billion Suns.
“Measurements of these massive black holes will
help us understand how their host galaxies were assembled, and how the holes
achieved such monstrous mass,” McConnell told the New York Times.