Important notice about STEREO Behind
This STEREO image and video clip of the Sun in extreme ultraviolet light (April 18-19, 2008) showcase a group of active regions near the Sun's left edge over about 40 hours. These slowly changing loops are visible because particles are spinning along and tracing magnetic field lines that rise up and above several active regions. With frames being taken every two and a half minutes, scientists can observe the activity along these magnetic field lines in exquisite detail. Active regions are areas of intense magnetic activity that appear brighter in extreme UV light, in this case the wavelength of 171 Angstroms. The images were captured by the Behind spacecraft.
Last Revised: March 19, 2018 15:00:39 UTC
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