"The greatest astronomers of the first half of the 20th century were the astrophysicists. For example, Arthur Eddington, Cecilia Payne, Hans Bethe, and Subrahmanyan Chandrasekhar elucidated the physical nature of stars using the new quantum theories of atomic, nuclear and particle physics. In recent decades, about half of the prizes of the American Astronomical Society are awarded for work in astrophysics and half in astronomy."