NASA's STEREO (Ahead) spacecraft observed this visually stunning prominence eruption on Sept. 29, 2008 in the 304 wavelength of extreme UV light. It rose up and cascaded to the right over several hours, appearing something like a flag unfurling, as it broke apart and headed into space. 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. (NASA/STEREO) #
http://www.boston.com/bigpicture/2008/10/the_sun.html