Cecilia Helena Payne-Gaposchkin (May 1900 – December was a British-American astronomer and astrophysicist who, in proposed in her Ph. thesis an explanation for the composition of stars in terms of the relative abundances of hydrogen and helium. Tilda Swinton, Maria Callas, Women In History, World History, Great Women, Amazing Women, Amazing People, Ute Lemper, Kings & Queens