Another particularly important but less visible set of solar features are known as faculae. These structures are smaller than sunspots but often more numerous, as can be seen from images of the Sun taken through a filter which shows ionized calcium (see the first page). Curiously, they are brighter than their surroundings, and more so at the edge of the Sun than at the center. Faculae are associated with strong magnetic field regions, like sunspots are, but their detailed character is not well understood.
Approved by Peter Fox
Last revised: Mon Apr 10 15:08:11 MDT 2000