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.
Powerful solar flare and running penumbral waves
Credit: IRIS, LMSAL/NASA, Milan Gosic
On 22-Oct-2014, IRIS observed a fierce active region. The movie shows multiple explosive events such as mini flares. Closer to the end of the movie, we can even see an M8.7 class flare: a sudden flash of light visible on the solar surface. During flares, a large amount of magnetic energy is released and transferred into heating of the chromosphere and corona. Meanwhile, there are series of ripple-like features generated within the sunspot (dark structure on the left) that travel outward. These features are known as running penumbral waves. Their lifetime is about 3 to 5 minutes and they provide important information about energy transfer through the solar atmosphere and the physical nature of sunspots.