Multi-wavelength flare The Sun unleashed a series of flares over several days, of which this one on September 6, 2011 was the largest, an X 2.1 flare (major). The still shows the flash of the flare in one wavelength of extreme ultraviolet (UV) light from SDO. The video clip presents a series of five stills taken at the same time in various wavelengths of UV light. The brightness of the flare causes very bright saturation and 'blooming' above and below the flare region on the CCD detector and caused extended diffraction patterns to spread out to some degree in all the images.