From AMS Glossary
Bright structure suspended above the solar limb by magnetic fields—known as a filament when observed on the solar disk. It is most often and more clearly visible when observed in H-alpha light and may be seen when present along the edge of the sun during a total solar eclipse. When a prominence becomes active in motion, it is known as an active prominence region (APR). A prominence that ejects from the sun is known as an eruptive prominence on the limb (EPL).
Term edited 14 August 2018.