Ejnar Hertzsprung

Hertzsprung, Ejnar 

Born Oct. 8, 1873, in Frederiksberg, Denmark; died Oct. 21, 1967, in Tølløse, Denmark. Astronomer. Member of the Dutch and Danish academies of sciences and corresponding member of the Paris Academy of Science.

Hertzsprung, who was educated as a chemical engineer, was a professor of astronomy at Göttingen, Potsdam, and Leiden. From 1935 to 1945 he was director of the Leiden Observatory. He discovered (1905, 1907) the division of stars of spectral classes G, K, and M into “giants” and “dwarfs” and the existence of a relationship between the absolute magnitude and spectral class of stars. (Subsequently this relationship was examined in detail by the American astronomer H. Russell and was named the Hertzsprung-Russell diagram.) Hertzsprung applied photography for the first time (1914-19) to the study of binary stars.

REFERENCES

Pannekoek, A. Istoriia astronomii. Moscow, 1966. (Translated from English.)
Strand, K. “Ejnar Hertzsprung, 1873-1967.” Astronomical Society of the Pacific. Publications, 1968, vol. 80, no. 472, pp. 50-56.