This sequence of images shows the Sun as it appears in four different frequencies of ultraviolet radiation, along with a visible-light view for comparison. All four of the ultraviolet images are from the high energy Extreme Ultraviolet (EUV) end of the UV spectrum. Notice how different features on the "surface" of the Sun and in the solar atmosphere are visible in the different images. Notice also that bright regions in the UV images, which indicate large emissions of energy, are often located at or above the sunspots in the visible light view. These images were captured by the SOHO satellite on February 3, 2002, shortly after "solar max" when the Sun was quite active.
Images courtesy SOHO (ESA & NASA). Animation by Windows to the Universe staff (Randy Russell).