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.
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11 Sep 2023
A Rainy Day above the West Limb
Credit: IRIS, LMSAL/NASA, Chad Madsen, SAO
This video features an excellent example of a peculiar phenomenon known as coronal rain. This occurs when an energetic, impulsive event like a solar flare injects material at extremely high temperatures in the region above the solar surface. This material gets trapped by the Sun's magnetic field where it slowly cools. Initially, the material is too hot for IRIS to detect. When the suspended material cools to a temperature sensitive to IRIS, it suddenly appears above the limb as if it condensed out of nothing. This happens first to the material furthest from the solar surface, giving the appearance of waterfalls flowing along magnetic field loops toward the surface.