Notable Physicists: Cecilia Payne-Gaposchkin

Cecilia Helena Payne-Gaposchkin (10 May 1900 – 7 December 1979) was a British-born American astronomer and astrophysicist who proposed in her 1925 doctoral thesis that stars were composed primarily of hydrogen and helium. 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.