US physicist and astronomer whose work on the spectrum of the solar chromosphere revolutionized much of solar astronomy. He was one of the first scientists to combine astronomy with atomic physics.

Menzel was born in Florence, Colorado, and studied at the University of Denver. At Princeton University as a graduate assistant, he learned astrophysics from Henry Russell, the co-originator of the Hertzsprung-Russell diagram. In 1932, Menzel joined Harvard University Observatory, where he was to become director some 30 years later. The coronagraph he constructed there was the beginning of High Altitude Observatory for solar physics research. During his career Menzel took part in the setting-up or development of several observatories in the USA. He retired from Harvard 1971 to become scientific director of a company manufacturing antennae for communications and radioastronomy.
In addition to this work, Menzel devised a technique for computing the temperature of planets from measurements of water cell transmissions and he made important contributions to atmospheric geophysics, radio propagation, and even lunar nomenclature. He also held patents on the use of gallium in liquid ball bearings and on heat transfer in atomic plants.