Joseph von Fraunhofer
A German physicist and optical instrument maker, Joseph von Fraunhofer (1787-1820) is best known for his investigation on the dark lines within the Sun's spectrum. Now named after him has the Fraunhofer lines, they correspond to wavelengths of light absorbed by chemical elements in the outer parts of the Sun's atmosphere. Fraunhofer's observations are now used to find out the spectrums of other stars.
- Universe by Martin Rees, ISBN 978-1-4093-7650-7