Friday, 7 July 2017

The Mystery of Coronal Heating

For more than a half-century, astronomers have tried to figure out what causes the corona to be so hot.  It is one of the most vexing problems in astrophysics.
Solar physicist Bart De Pontieu of the Lockheed Martin Solar & Astrophysics Laboratory says, “The problem of coronal heating was first discovered in the 1940s. The problem involves a variety of complex physical processes that are difficult to directly measure or capture in theoretical models.”
On June 27, 2013, with campfires blazing around the USA, NASA launched the Interface Region Imaging Spectrograph (IRIS) - a space-based solar observatory designed to get to the bottom of how the solar atmosphere is heated.
“IRIS studies the transition region between the sun’s surface and the corona,” explains De Pontieu, who is the science lead of the observatory. “It can track the temperature and motions of hot gas at unprecedented spatial (0.33 arcsec), temporal (2 s) and spectral (2 mi/s) resolution.”
Most researchers agree that the corona is probably heated in several different ways. For instance, plasma waves from the sun can rise into the corona and crash, depositing their energy there. At the same time, “heat bombs” could be going off. These explosions happen when magnetic fields in the corona criss-cross and realign, exploding like a miniature solar flare.

No comments:

Post a Comment