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.
Rare observation of a solar prominence formation
Credit: IRIS, LMSAL/NASA, Milan Gosic
On 26-Feb-2019 IRIS had a rare opportunity to observe the formation process of a solar prominence seen at the west limb. Prominences are made of cool gas that exists at coronal heights. They are much cooler than the surrounding million Kelvin hot coronal plasma (about 100 times), but also much denser (about 100 times). Bright pixels that are clearly visible from time to time are the result of high energy particles hitting our CCD camera when IRIS is passing through the Earth's radiation belts, and are not caused by solar radiation.