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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4 Aug 2016
One Loop, Two Loop, Hot Loop, Cool Loop
Credit: IRIS, LMSAL/NASA, Kathy Reeves
A faint, fuzzy magnetic loop appears on the limb at the beginning of this 1330 SJI movie. It fades away, and is replaced by a sharper, more well-defined loop about an hour and a half later. The first loop is a hot loop from Fe XXI (formed at 10 million degrees) emitting in the 1330 A bandpass. Later it cools down to the cooler temperatures of C II (30,000 degrees), which also emits in this bandpass. It takes more than an hour for the loop to cool from 10 million degrees to 30,000 degrees.