Fraunhofer, Joseph von
Pronunciation: /ˈfraʊnˌhəʊfə, ˈfraʊnˌhoːfɐ/
Definition of Fraunhofer, Joseph von
- (1787–1826), German optician and pioneer in spectroscopy. He observed and mapped the dark lines in the solar spectrum ( Fraunhofer lines) which result from the absorption of particular frequencies of light by elements present in the outer layers; these are now used to determine the chemical composition of the sun and stars.