<Tr> <Th> Doctoral students </Th> <Td> Helen Sawyer Hogg, Joseph Ashbrook, Frank Kameny, Frank Drake, Paul W. Hodge </Td> </Tr> <Tr> <Th_colspan="2"> Signature </Th> </Tr> <P> Cecilia Helena Payne - Gaposchkin (May 10, 1900--December 7, 1979) was a British--American astronomer and astrophysicist who, in 1925, proposed in her Ph. D. thesis an explanation for the composition of stars in terms of the relative abundances of hydrogen and helium . </P> <P> Cecilia Helena Payne was one of three children born in Wendover, England, to Emma Leonora Helena (née Pertz) and Edward John Payne, a London barrister, historian and accomplished musician . Her mother came from a Prussian family and had two distinguished uncles, historian Georg Heinrich Pertz and the Swedenborgian writer James John Garth Wilkinson . Cecilia Payne's father died when she was four years old, forcing her mother to raise the family on her own . </P>

Who discovered the sun is made of hydrogen