Charles Greeley Abbot was an American astrophysicist and the fifth secretary of the Smithsonian Institution, serving from 1928 until 1944. Abbot went from being director of the Smithsonian Astrophysical Observatory, to becoming Assistant Secretary, and then Secretary of the Smithsonian Institution over the course of his career. As an astrophysicist, he researched the solar constant, research that led him to invent the solar cooker, solar boiler, solar still, and other patented solar energy inventions.

The Smithsonian Astrophysical Observatory (SAO) is a research institute of the Smithsonian Institution, concentrating on astrophysical studies including galactic and extragalactic astronomy, cosmology, solar, earth and planetary sciences, theory and instrumentation, using observations at wavelengths from the highest energy gamma rays to the radio, along with gravitational waves. Established in Washington, D.C., in 1890, the SAO moved its headquarters in 1955 to Cambridge, Massachusetts, where its research is a collaboration with the Harvard College Observatory (HCO) and the Harvard University Department of Astronomy. In 1973, the Smithsonian and Harvard formalized the collaboration as the Center for Astrophysics | Harvard & Smithsonian (CfA) under a single Director.