Annie Jump Cannon (1863–1941)

Born on 11 December 1863 in Dover, Delaware, Annie Jump Cannon was an astronomer who, by sorting through the spectra of some 400 000 stars, developed a stellar classification system that is still used today. Cannon studied physics and astronomy at Wellesley College. After graduating in 1884, she spent the next decade at home in Delaware and traveling. After her mother died in 1894, Cannon returned to Wellesley, and the following year she entered Radcliffe College, a liberal arts college for women associated with Harvard College, which accepted only men at that time. In 1896 she became an assistant to Edward Charles Pickering, director of the Harvard College Observatory. Pickering recruited female “computers” to collect, analyze, and classify as many stellar spectra as possible. Cannon would spend the next four decades at Harvard, where she established a reputation as a keen observer, able to recognize at a glance a star’s key characteristics. She not only classified several hundred thousand stars for the Henry Draper Catalogue but also developed the famous OBAFGKM star classification system. Although named curator of astronomical photographs at Harvard in 1911, it was only in 1938, just two years before she retired, that she was granted a regular Harvard appointment as an astronomer. Over her career, Cannon earned numerous honors and awards, including the 1931 Henry Draper Medal of the National Academy of Sciences. She was the first woman to receive an honorary doctorate of science from Oxford University (1925) and the first woman elected an officer of the American Astronomical Society (AAS). Today AAS gives the Annie Jump Cannon Award in Astronomy to a postdoctoral woman researcher each year. Cannon died in 1941, at the age of 77. (Photo credit: New York World-Telegram, the Sun newspaper, PD-US)

Date in History: 11 December 1863