Definition of Faculae:

part of speech: noun plural

Spots on the sun which appear brighter than the rest of its surface.

Usage examples:

• It is also marked here and there by long streaks of light, called faculae which look like foam flecks below a cataract. Bill Nye in "Remarks".

• All groups of Sun- spots and faculae have been numbered, and the dates of their first and last appearances entered up to the present time. George Biddell Airy in "Autobiography of Sir George Biddell Airy".