facula

American  

[fak-yuh-luh] / ˈfæk yə lə /

noun

Astronomy.

plural

faculae

1. an irregular, unusually bright patch on the sun's surface.

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facula British  

/ ˈfækjʊlə /

noun

1. any of the bright areas on the sun's surface, usually appearing just before a sunspot and subject to the same 11-year cycle

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facula Scientific  

/ făk′yə-lə /

plural

faculae

1. 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.

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Other Word Forms

• facular adjective

Etymology

Origin of facula

1700–10; < Latin: little torch, equivalent to fac- (stem of fax ) torch + -ula -ule

Example Sentences

Quippe aliquo, reor, ille novus jam nictat in astro, Et se nocturna parvus habet facula.

From The Complete Works of Richard Crashaw, Volume II (of 2) by Crashaw, Richard

He considers it indeed "highly probable that the preparatory sign of a new spot is always a small, bright patch of facula."

From A Popular History of Astronomy During the Nineteenth Century Fourth Edition by Clerke, Agnes M. (Agnes Mary)