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Magnetic Field Uses Sound Waves to Ignite Sun's Ring of Fire

05.29.07


Sound waves escaping the Sun's interior create fountains of hot gas that shape and power the chromosphere, a thin region of the sun's atmosphere which appears as a ruby red "ring of fire" around the moon during a total solar eclipse, according to research funded by NASA and the National Science Foundation (NSF). These results were presented May 29, at the American Astronomical Society Meeting in Honolulu, Hawaii.

The chromosphere is important because it is largely responsible for the deep ultraviolet radiation that bathes the Earth, producing our atmosphere's ozone layer, and it has the strongest solar connection to climate variability. The new result also helps explain a mystery that's existed since the middle of the last century -- why the chromosphere (and the tenuous corona above) is much hotter than the visible surface of the star. "It's like getting warmer as you move away from the fire instead of cooler, certainly not what you expect," said Scott McIntosh, a researcher at Southwest Research Institute, Boulder, Colo.

“This work finds the missing piece of the puzzle that has fascinated many generations of solar astronomers. When you fit this piece in place, our vision of the chromosphere becomes clear,” said Alexei Pevtsov, Program Scientist NASA Headquarters, Washington.
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