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A German pioneer in optics, Joseph von Fraunhofer discovered in 1814 that the spectrum of the sun had 574 lines in it. Using the spectroscope he had invented Fraunhofer examined the spectrum of several bright stars and described that the lines in each were somewhat different.
Kirchhoff and Bunsen in 1859 explained that these lines represented absorption of specific wavelengths of light by elements in the fiery furnace of the sun. Astronomers now had the opportunity to examine the composition of stars with the spectroscope. They showed that they often had in them the same elements known here on earth through laboratory experiments.
In the 1860s William Huggins and his wife Margaret at in his observatory near London added a new dimension to spectroscopy. Looking at the spectrum of several stars they noted that the lines of some were shifted toward the violet but more often they were shifted toward the red. He correctly deduced that this was an expression of the newly described Doppler effect in which sound from an approaching vehicle was raised in pitch because the waves were compressed and sound from a retreating vehicle were lower in pitch because the waves were stretched out.
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