Gaposchkin, Cecilia Helena Payne, 1900-1979

Cecilia Payne-Gaposchkin; British-born American astronomer; Cecilia Payne-Gaposchkin, original name in full Cecilia Helena Payne, (born May 10, 1900, Wendover, Eng.—died Dec. 7, 1979, Cambridge, Mass., U.S.), British-born American astronomer who discovered that stars are made mainly of hydrogen and helium and established that stars could be classified according to their temperatures.

Cecilia Helena Payne-Gaposchkin (born Cecilia Helena Payne, May 10, 1900, Wendover, England – December 7, 1979, Cambridge, Massachusetts) was a British-born American astronomer and astrophysicist who proposed in her 1925 doctoral thesis that stars were composed primarily of hydrogen and helium.[1] Her groundbreaking conclusion was initially rejected because it contradicted the scientific wisdom of the time, which held that there were no significant elemental differences between the Sun and Earth. Independent observations eventually proved she was correct.