Facula

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For the genus of gossamer-winged butterflies, see Facula (butterfly).

A facula (plural: faculae), Latin for "little torch", is literally a "bright spot." The term has several common technical uses. It is used in planetary nomenclature for naming certain surface features of planets and moons, and is also a type of surface phenomenon on the Sun. In addition, a bright region in the projected field of a light source is sometimes referred to as a facula, and photographers often use the term to describe bright, typically circular features in photographs that correspond to light sources or bright reflections in a defocused image.

Solar faculae are bright spots that form in the canyons between solar granules, short-lived convection cells several thousand kilometers across that constantly form and dissipate over timescales of several minutes. Faculae are produced by concentrations of magnetic field lines.

The chromosphere is above the photosphere. Solar energy passes through this region on its way out from the center of the Sun. Faculae and flares arise in the chromosphere. Faculae are bright luminous hydrogen clouds which form above regions where sunspots are about to form. Flares are bright filaments of hot gas emerging from sunspot regions. Sunspots are dark depressions on the photosphere with a typical temperature of 4,000°C (7,000°F).

References

source: http://www.solarviews.com/eng/sun.htm