Nasa: Magnetic braids in Sun’s atmosphere

A Nasa space telescope has spotted surprising 'magnetic braids' of super-hot matter in the Sun's outer atmosphere, a finding that scientists claim may explain the star's mysteriously hot corona.

The discovery, made by Nasa's High-Resolution Coronal Imager, or Hi-C, also may lead to better space weather forecasts, the scientists added.

Jonathan Cirtain, a solar astrophysicist at Nasa's Marshall Space Flight Center, Huntsville and his team launched the 9.5-inch (24 centimetres) telescope last July on a 10-minute flight just beyond Earth's atmosphere to study the corona, the Sun's million-degree outer atmosphere.

The telescope snapped 165 photos in stunning detail before parachuting back to Earth, Space.com reported.

The surface of the Sun is unsurprisingly hot, up to 6,125° Celsius. Bizarrely, however, the corona - the outer atmosphere far above the Sun's surface - is hotter by a thousandfold, even in the absence of solar flares.

Scientists recently found that powerful magnetic waves rippling from below the Sun's surface may heat the corona by 1.5 million degrees Celsius. However, that alone would not account for the corona's ultra-hot temperatures.

Now high-resolution images of the Sun's corona support the idea of magnetic braids generating tremendous amounts of heat, possibly enough to explain the readings of up to 6 mn°C.

"What we have observed is a bundle of magnetic fields, wrapped about several other bundles to form a magnetic bundle ensemble," Cirtain told the website.