Any of various large bright spots or veined patches on the surface of a planet or other solar system body, or on the sun's photosphere.
A bright, cloudlike structure on the Sun's surface, ascending several hundred kilometers above the photosphere and often associated with sunspots. Faculae are formed when a strong magnetic field heats a region of the photosphere to higher temperatures than the surrounding area. They occur all over the Sun but are usually only visible near the limb (the outer edge of the Sun's apparent disk), where the photosphere appears dimmer than in the center.
Origin of facula
- Latin small torch diminutive of fax fac- torch
From American Heritage Dictionary of the English Language, 5th Edition