Annie Jump Cannon

Annie Jump Cannon sits at her desk at the Harvard College Observatory, papers spread in front of her and bookshelves along the wall behind. First hired to carry out astronomical calculations, she became one of the leading American astronomers. Much of her work happened at a desk like this one rather than at a telescope: she sorted stars by the patterns in their photographed spectra, and her O, B, A, F, G, K, M sequence is still how astronomers classify stars.