Annie Jump Cannon

Annie Jump Cannon was born in Delaware in 1863. Her mother taught her the constellations from the attic, and she went to Wellesley College to study physics, graduating in 1884. At some point in her twenties, possibly after scarlet fever, she lost most of her hearing, and it worsened through her life. She spent the ten years after college at home, taking photographs and travelling, with no obvious path into science.

Her mother's death in 1894 sent her back to Wellesley as an assistant and then to Radcliffe as a special student, which gave her access to the Harvard College Observatory. In 1896 she joined the women there who examined photographic plates for Edward Pickering, at wages a fraction of what men were paid.

Her job was to classify the spectra of stars, and she was extraordinarily good at it. Where others took minutes over a spectrum she took seconds, and her judgements were consistent. She reorganised the existing classes into a single sequence by temperature, the O B A F G K M order every astronomy student still learns, and then applied it, over the following decades, to more than 350,000 stars. The Henry Draper Catalogue, published between 1918 and 1924, is essentially her work.

Oxford gave her an honorary doctorate in 1925, the first to a woman. Harvard did not give her a formal faculty appointment until 1938, when she was 74. She died in 1941.