Born in Delaware, Annie Jump Cannon was introduced to stargazing by her mother. She studied physics and astronomy at Wellesley College in Massachusetts, and after graduating, became focused on photography. But after the death of her mother in 1894, she dove back into the world of astronomy.
Cannon enrolled as a special student at Radcliffe College (the women’s college affiliated with the then all-male Harvard College), where she began work as part of a group known as “Pickering’s women.” These women were designated to conduct research and calculations under Harvard Observatory Director Edward Pickering, and were often referred to as computers. Following in the footsteps of insightful contemporaries such as Williamina Fleming and Antonia Maury, Cannon began examining image plates of various stars. Her analysis of over 1,100 stars led her to refine a method of classification based on their colors (which are related to their temperatures). The mnemonic device “Oh! Be A Fine Girl — Kiss Me!” is now a well-known way to remember the OBAFGKM classes of the Harvard spectral classification. The work was eventually published in the Henry Draper Catalogue of classification and officially adopted by the International Astronomical Union in 1922.
The extensive work bolstered her career, earning Cannon the position of curator of observational photographs at Harvard, which led to many more discoveries of variable stars and novae. She also received a Ph.D. from Groningen University in the Netherlands — the first woman to do so — as well as an honorary doctorate from Oxford University, among many more achievements.
Cannon passed away on April 13, 1941. But her legacy lives on: In 1933, the American Astronomical Society established the Annie Jump Cannon Award for outstanding current and future potential research by a female postdoctoral researcher. It is given to a North American female astronomer within five years of receiving her Ph.D. Among the winners are scientists who have advanced our understanding of the life cycle of stars, gravitational lensing, and more.
