Sunlight spectrum Fraunhofer absorption lines

Fraunhofer spectrum spect The absorption lines in sunlight, due to the cooler outer layers of the sun s atmosphere. fraun,hof-or. spek-trom freeboard analychem The space provided above the resin bed in an ion-exchange column to allow for expansion of the bed during backwashing. fre,bord ( free cyanide chem Cyanide not combined as part of an ionic complex. Ifre sT-3,nTd ... 

Fraunhofer lines - Sharp absorption lines in the spectrum of sunlight, caused by absorption of the solar blackbody radiation by atoms near the sun s surface. 

Fraunhofer s lines n. When sunlight is examined through a spectroscope it is found that the spectrum is traversed by an enormous number of dark lines parallel to the length of the slit. These dark lines are known as Fraunhofer s lines. Kirchoff conceived the idea that the sun is surrounded by layers of vapors which act as filters of the white light arising from incandescent solids within and which abstract those rays which correspond in their periods of vibration to those of the components of the vapors. Thus reversed or dark lines are obtained due to the absorption by the vapor envelope, in place of the bright lines found in the emission spectrum. 

Figure 1 The Kirchoff experimental apparatus as illustrated in a book by Tyndall. The absorption spectrum of sodivun atoms appears on the screen S when a sodium salt is introduced into a flame B. The sodium D line is superimposed on the Fraunhofer spectrmn of sunlight, which passes through lens L, and is dispersed by a prism P.

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