The American astronomer Antonia Caetana de Paiva Pereira Maury (1866-1952). In 1889 she became an assistant to Edward Pickering at the Harvard College Observatory joining an unusually large group of women of whom the most eminent were Annie Cannon and Henrietta Leavitt. Much of her work was on the classification of stellar spectra for the Henry Draper star catalogue. She proposed that not just the absence or presence of a particular spectral line was important but also its appearance. This has been described as the first step in using spectroscopic criteria for the luminosities of stars. She also spent many years studying and detecting spectroscopic binary stars.