added 11/20/02

Binary Black Holes Found in Nearby Galaxy


In late 2002, the orbiting Chandra X-ray Observatory discovered two super-massive black holes lurking in a single galaxy that eventually will spiral together in a catastrophic merger, perhaps sending gravity waves rippling through the cosmos if indeed gravity waves exist. The black holes were discovered in galaxy NGC 6240, an exceptionally bright star swarm 400 million light years away.

A black hole is a point in space that is so dense with matter that its gravitational field will not let anything (except gravity!) escape, not even light. Stellar black holes, equal to 3.5 to about 15 solar masses, can be formed by the collapse of a single massive star. But galactic black holes, such as those in NGC 6240, are much larger, equal perhaps to millions of solar masses, and are usually found at the center of galaxies. The Milky Way, home galaxy of the sun and its planets, is thought to have a black hole at its center.

"The detection of a binary black hole supports the idea that black holes can grow to enormous masses in the centers of galaxies by merging with other black holes," said Stefanie Komossa, of the Max Planck Institute for Extraterrestrial Physics in Germany, in a statement. "This is important for understanding how galaxies form and evolve."

Of course, the above statement is only true if that is indeed how the central black holes formed in galaxies. One must first ask, how did two such massive black holes manage to gather so much mass in so short a time period if they had to first start with star formation and then go through the stage of forming small black holes? On the other hand, if they were originally formed in a previous "Big Crunch", then the galaxy could be the result of the central black hole or holes rather than the cause of it!


In another study, French and Argentine astronomers said that observations by the Hubble Space Telescope and ground-based telescopes have detected a stellar black hole streaking across the Milky Way at about 250,000 miles an hour. A companion star is being dragged along and slowly devoured by the black hole.