Important notice about STEREO Behind
A Solar Prominence per Quadrant
A STEREO (Ahead) spacecraft observed several solar prominences rise and gyrate above the Sun over a two-day period (Aug. 15-16, 2008), with the largest one arcing a distance at least equal to 30 Earth diameters. They are spread out with one in each quadrant. Magnetic forces control solar prominences that rise above the Sun's surface. The prominences were seen in the 304 Angstroms wavelength of ultraviolet light. The material observed is actually ionized Helium at about 60,000 degrees. Prominences are relatively cool clouds of gas suspended above the Sun and controlled by magnetic forces. They can last from hours to months, but most usually remain for just a few days.
Last Revised: March 19, 2018 15:00:39 UTC
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