Move over, Milky Way

Evidence points to huge black hole

WASHINGTON -- Astronomers using the Hubble Space Telescope have found evidence of a black hole 3 million times the mass of the sun in the center of a galaxy that is a cosmic neighbor of the Milky Way, officials said Wednesday.

Tod R. Lauer of the National Optical Astronomy Observatories in Tucson, Ariz., said that final proof of a black hole in the nearby galaxy M32 will require more study, but he said there is strong evidence.

"I would say the case is very good," Lauer said. "I would be surprised if M32 turns out not to be a black hole."

M32 is 2.3 million light-years from Earth, a distance close enough in astronomical terms to be considered a neighbor of the Milky Way. A light-year is the distance light travels in a vacuum in one year, about 6 trillion miles.

The existence of a black hole was predicted in Einstein's general theory of relativity, but astronomers have not found absolute proof. Black holes are thought to form when a massive star or a group of stars collapses inward, forming an object so gravitationally dense that not even light or any form of radiation can escape. As a result, black holes cannot be seen by telescopes or other instruments.

Lauer said he and his team concluded that M32 may contain a black hole by measuring the movement of stars within the galaxy and by studying the star density near the galaxy center. He said they found that M32 is the densest star system known, containing about 400 million stars within a diameter of only 1,000 light-years. By contrast, the Milky Way is thought to be 100,000 light-years across.