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 spectrum it represented was crossed by numerous Fraunhofer lines, and by no others.

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

In astronomical and astrophysical matter italicize: The lower-case letters designating certain Fraunhofer lines: a, b, g, h.

From The Uses of Italic A Primer of Information Regarding the Origin and Uses of Italic Letters by Hamilton, Frederick W. (Frederick William)

It needs only a moment's consideration of the meaning at last found for the Fraunhofer lines to see the incompatibility of the new facts with the old conceptions.

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

Kirchhoff’s principle, accordingly, not only afforded a simple explanation of the Fraunhofer lines, but availed to found a far-reaching science of celestial chemistry.

From Encyclopaedia Britannica, 11th Edition, Volume 2, Slice 7 "Arundel, Thomas" to "Athens" by Various

If the luminous body approaches swiftly, its Fraunhofer lines are shifted from their normal position towards the violet end of the spectrum; if it recedes, the lines shift in the opposite direction.

From A History of Science — Volume 3 by Williams, Henry Smith