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 Agnes M. (Agnes Mary) Clerke

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 Agnes M. (Agnes Mary) Clerke

Once more the wonderful Fraunhofer lines came to the rescue.

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

Vogel’s observations on the 9th of June 1871, of differences due to the sun’s rotation in the refrangibility of Fraunhofer lines derived respectively from the east and west limbs.

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

It is amply possible that the absorptive strata producing the Fraunhofer lines, significant, by their varying displacements at either limb, of the inferred varying rates of rotation, may gyrate more slowly than the spot-generating level.

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