Henry Norris Russell

Russell, Henry Norris (1877–1957), U.S. astronomer. His theory of stellar evolution led to the construction of the Hertzsprung-Russell diagram, work done independently of Ejnar Hertzsprung, showing the relation between a star's brightness and color. He also determined the chemical-element content of the solar atmosphere and analyzed the spectra of various chemical elements.

See also: Astronomy.