Sept. 20 — Astronomers have pinpointed with unprecedented accuracy an immense black hole with a mass of more than 2 million suns at the center of the spiral of stars that is the Milky Way galaxy.
THE RESEARCHERS have spent four years watching stars spin closer and faster around the black hole, an illustration of its powerful gravitational tug.
Researchers at the University of California at Los Angeles, led by Andrea Ghez, used the Keck telescope in Hawaii to measure tiny differences in infrared images of stars orbiting the estimated center of the galaxy near a point called Sagittarius A*.
Radio waves emitted by Sagittarius A* make it relatively easy to find through a thick veil of dust and gas, but measuring the orbital paths of nearby stars has been difficult.
The velocity, or speed of the stars, had been roughly measured, but the UCLA team took it a step further by using the infrared images of three stars to measure their acceleration — or how fast the stars were speeding up — and triangulate their center of rotation.
“And the nice thing is they intersect right on top, almost exactly, of this radio source, Sagittarius A*, which people have long suspected is a black hole,” said John Kormendy, an astronomer at the University of Texas in Austin.
Want to learn more? http://www.msnbc.com/news/463968.asp
----------------------------
Alien - Administrator / Owner
["Everything was true. God was an alien. Oz really is over the
rainbow. ...and Midian is where the monsters live." -Nightbreed]
THE RESEARCHERS have spent four years watching stars spin closer and faster around the black hole, an illustration of its powerful gravitational tug.
Researchers at the University of California at Los Angeles, led by Andrea Ghez, used the Keck telescope in Hawaii to measure tiny differences in infrared images of stars orbiting the estimated center of the galaxy near a point called Sagittarius A*.
Radio waves emitted by Sagittarius A* make it relatively easy to find through a thick veil of dust and gas, but measuring the orbital paths of nearby stars has been difficult.
The velocity, or speed of the stars, had been roughly measured, but the UCLA team took it a step further by using the infrared images of three stars to measure their acceleration — or how fast the stars were speeding up — and triangulate their center of rotation.
“And the nice thing is they intersect right on top, almost exactly, of this radio source, Sagittarius A*, which people have long suspected is a black hole,” said John Kormendy, an astronomer at the University of Texas in Austin.
Want to learn more? http://www.msnbc.com/news/463968.asp
----------------------------
Alien - Administrator / Owner
["Everything was true. God was an alien. Oz really is over the
rainbow. ...and Midian is where the monsters live." -Nightbreed]