Space

NASA Scope Reveals Magnetic 'Braids' in Sun's Corona; Hot and Hotter

Catherine Griffin
First Posted: Jan 24, 2013 08:49 AM EST

There's a reason why the sun is so hot--braids. Scientists have recently found that powerful magnetic waves moving from below the sun's surface in the form of "braids" generate tremendous amount of heat--perhaps enough to explain readings of up to 10.8 million degrees Fahrenheit.

Jonathan Cirtain, a solar astrophysicist at NASA's Marshall Space Flight Center, and his team launched a 9.5-inch telescope last July on a 10-minute flight in order to study the corona, the sun's outer atmosphere. The telescope, named the High-Resolution Coronal Imager (Hi-C), snapped 165 photos during its mission before parachuting back to Earth.

The photos are stunning, showing a wealth of detail that scientists analyzed afterward. For years, researchers wondered exactly why the sun's outer atmosphere was so hot. The surface of the sun is only about 11,000 degrees, while its corona is hotter by a thousandfold. The images, however, revealed what might be the reason for this difference.

Scientists have recently found that powerful magnetic waves could heat the corona by 2.7 million degrees. However, these waves wouldn't be able to account for the corona's temperatures. The images, though, provide another explanation. Researchers noticed that the magnetic structures formed into "braids"--loops, arches and curves that rise from the sun. These formations eventually become unstable and allow individual magnetic field lines of force to interact with them. It can release vast amounts of energy which can heat plasma or accelerate solar flares while heating the corona.

While these findings, detailed in the journal Nature, would certainly explain the super-heated corona, scientists still have their doubts. They admitted that it is possible that the braids they saw were not bundles of magnetic fields but instead, sets of many nested magnetic loops. These would store less energy and would not explain the full reason why the corona is so hot.

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