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Study describes star bar at Milky Way's core

MADISON, Wis. -- From Earth, the Milky Way galaxy is a band of stars that lights up the night sky. From outside the galaxy looking in, astronomers say it is an entirely different picture.

After completing a detailed analysis, astronomers say a long bar of stars cuts on an angle through the center of the galaxy that includes the sun and Earth.

The team of astronomers used NASA's Spitzer Space Telescope to survey more than 30 million stars in the center of the Milky Way. The orbiting infrared telescope allowed the astronomers to see bright stars through clouds of interstellar dust to draw a vivid portrait of the center of the galaxy.

''We're pretty certain of the extent and orientation of this bar because we got more data than anybody else that has ever brought to bear on the problem by a long shot," said Ed Churchwell, a professor of astronomy at the University of Wisconsin at Madison who collaborated on the project.

Robert Benjamin, a physics professor at the university's Whitewater campus and lead author of the study, said the new portrait would help astronomers understand the inner regions of the Milky Way.

The study should put to rest the idea held by some astronomers that an ellipse is at the center of the galaxy's swirling arms, Churchwell said.

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