Germanphysicist. With the chemist Robert Wilhelm Bunsen (1811–99) he established the principles of spectral analysis. In 1859 he reasoned that the Fraunhofer lines in the solar spectrum indicated that light from the photosphere was being absorbed at those wavelengths by the Sun's atmosphere. Furthermore, he realized that the Fraunhofer D lines were produced by sodium in the Sun's atmosphere, and other Fraunhofer lines would therefore reveal which other elements were present in the Sun. From then on, astronomical spectroscopy developed rapidly in the hands of others such as P. A. Secchi in Italy and W. Huggins in England.
Subjects: Astronomy and Astrophysics.