astronomers Take a Look Inside Red Giant Stars

[n2doc]

ScienceDaily (Mar. 30, 2011) — NASA's Kepler Mission is giving astronomers such a clear view of changes in star brightness that they can now see clues about what's happening inside red giant stars.

"No one anticipated seeing this before the mission launched," said Steve Kawaler, an Iowa State University professor of physics and astronomy and a leader of the Kepler Asteroseismic Investigation. "That we could see so clearly down below a red giant star's surface was unexpected."

The astronomers' preliminary findings are published in two papers, one in Science and the other in Nature (references below). Both papers describe how Kepler tracks tiny, regular changes in star brightness. Their regularity resembles steady drumbeats at different, precise rhythms.

Each rhythm can be thought of as an individual tooth of a comb. Astronomers have studied those oscillations from ground-based telescopes to determine star basics such as mass and radius. But they noticed departures from the steady patterns in the Kepler data -- "dandruff on the comb," Kawaler said.

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http://www.sciencedaily.com/releases/2011/03/110330131312.htm