H-Alpha emission features that resemble "flames" projecting beyond the edge of the sun, consisting of complex clouds or streamers of gas above or in the chromosphere. They generally come in two broad classes: Active (limb flares, surges, sprays, loops), and Quiescent (Quiet Region Filaments, Active Region Filaments).

Filaments seen on the limb of the Sun.

One of the most spectacular features of the Sun are solar prominences. They appear to stream, loop and arch away from the Sun. The most recognizable prominences appear as huge arching columns of gas above the limb (edge) of the Sun. However, when prominences are photographed on the surface of the Sun, they appear as long, dark, threadlike objects and are called filaments. Like sunspots, prominences are cooler (about 10,000 degrees C) in relation to the much hotter background of the Sun's outer atmosphere (about 1,500,000 degrees C). Prominences can also erupt from the Sun with a tremendous burst of energy.

See Solar Prominences.