On July 24, 1900, Cecilia Helena Payne was born in Wendover, Buckinghamshire, England — and went on to discover what the sun is made of, be told by the most respected astronomer in America that she was wrong, recant under pressure, and watch him publish the same finding four years later under his own name.

Payne received a scholarship to Cambridge in 1919, completed her studies, and discovered she could not receive a degree from Cambridge because she was a woman. She emigrated to the United States, took up a fellowship at Harvard College Observatory, and completed what has since been called the most brilliant PhD in astronomy ever written.

In her 1925 dissertation, Payne determined that hydrogen and helium were overwhelmingly the dominant elements in stellar composition — that stars were made almost entirely of these two gases. Henry Norris Russell, then the most prominent American astronomer, told her this was "almost certainly wrong" and persuaded her to include a disclaimer in the published dissertation.

In 1929, Russell published the finding himself and received credit for the discovery.

Payne continued at Harvard in a series of non-faculty positions. In 1956 she was appointed to the faculty — the first woman to hold a professorship at Harvard in any department — and served as department chair until 1960.

She died in 1979.