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.
IRIS scans flare ribbon
Credit: IRIS, LMSAL/NASA, Paul Bryans
The point where energy is released in a solar flare is typically higher in the Sun's atmosphere than can be seen with IRIS. But it produces energetic particles that then stream down towards the solar surface causing the bright "ribbons" we see in this movie. Studying these ribbons is crucial to understand the mechanisms responsible for the triggering of the flare. In this example, IRIS scans right across the post-flare ribbon, giving us a rare opportunity to learn more about the cause and effect of flares.