Annie Jump Cannon

Annie Jump Cannon
Credit: Smithsonian Institution (US)
Annie Jump Cannon (1863 –1941)

Annie was born on December 11, 1863, in Dover, Delaware, USA. She was always interested in space. Her mum encouraged this, and taught her the constellations. She studied physics and astronomy at Wellesley College, in the USA, graduating in 1884. In 1892, Annie went to Europe to photograph the solar eclipse. Two years later her mother died and Annie needed to return to the USA find work.

She got a job as a junior physics teacher. When she wasn't teaching she took extra courses in astronomy learning about spectroscopy and photography. In 1907, she finished her studies and got a master’s degree.

In 1896, Edward C. Pickering hired her as his assistant at the Harvard Observatory. She helped to map and classify stars for a new astronomical catalogue. Annie examined images, carried out calculations, catalogued photographs and classified stars. She was poorly paid, earning much less than the secretaries at Harvard.

Annie worked out a classification system for stars based on their surface temperatures. Her idea is known as the OBAFGKM system and is still used today.

Annie’s career lasted for more than 40 years. She classified more stars in her lifetime than anyone else (about 350,000). She published catalogues of star spectra and variable stars, including 300 that she had discovered.

Annie was the first person to get an honorary doctorate from Oxford University, UK. She became a curator at Harvard and won the Henry Draper Medal. There is now an Annie Cannon Prize, awarded to women who have made outstanding contributions in astronomy.