Fraunhofer lines

American  

plural noun

Astronomy.

1. the dark lines of the solar spectrum.

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Fraunhofer lines British  

/ ˈfraunhoːfər /

plural noun

1. a set of dark lines appearing in the continuous emission spectrum of the sun. It is caused by the absorption of light of certain wavelengths coming from the hotter region of the sun by elements in the cooler outer atmosphere

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Etymology

Origin of Fraunhofer lines

First recorded in 1830–40; named after J. von Fraunhofer

Example Sentences

See Examples For:

Fraunhofer lines

The whole range of Fraunhofer lines is visible when the light from a spot is examined with the spectroscope; but relatively few are widened.

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

These are frequently spoken of as Fraunhofer lines.

From Popular Science Monthly Oct, Nov, Dec, 1915 — Volume 86 by Anonymous

Consequently they are known as Fraunhofer lines, or dark absorption lines.

From Astronomy: The Science of the Heavenly Bodies by Todd, David Peck

This photograph completely confirms Young’s discovery, and shows the prominent Fraunhofer lines bright, the bright lines of the chromosphere spectrum being especially conspicuous.

From Encyclopaedia Britannica, 11th Edition, Volume 8, Slice 10 "Echinoderma" to "Edward" by Various

Examined by the spectroscope the Fraunhofer lines were extremely distinct, particularly two lines near the red end of the spectrum.

From Etna A History of the Mountain and of its Eruptions by Rodwell, G. F.