Hertzsprung-Russell diagram
noun
Hertz·sprung-Rus·sell diagram
ˈhertˌspru̇ŋˈrəsᵊl-
: spectrum-luminosity diagram
Word History
Etymology
after Ejnar Hertzsprung †1967 Danish astronomer and Henry Norris Russell †1957 American astrophysicist
First Known Use
1939, in the meaning defined above