Born in 1863, Delaware astronomer Annie Jump Cannon joined Harvard College Observatory’s “computers” in 1896 under Edward C. Pickering. Working at the objective-prism telescope’s plate stacks, she examined stellar spectra by eye, simplifying earlier schemes into the sequence O, B, A, F, G, K, M. Between 1918 and 1924 she led classification for the Henry Draper Catalogue, which listed 225,300 stars; extensions continued to 1936. Childhood scarlet fever left her largely deaf, so she relied on writ