IRIS Movie of the Day
At least once a week a movie of the Sun taken by NASA's Interface Region Imaging Spectrograph (IRIS) is posted by one of the scientists operating the instrument.
Flare Ribbons
Credit: IRIS, LMSAL/NASA, Aparna V.
Solar flares are energetic bursts of light and usually occurs in regions of strong magnetic field. When opposite magnetic field lines of these regions come close to each other, they can reconnect to release energy in sudden bursts. This usually occurs higher up in the solar atmosphere called the corona, and the plasma travel down from the top hits the solar surface and heats it up to cause bright ribbon like features that we see in the above movie. IRIS mainly observes the region on the Sun, the chromosphere and the transition region, where such brightening are commonly seen during and after flares.