Annie Jump Cannon
Did family influence the career you chose?
The “census taker of the sky" who cataloged more than 350,000 stars and revolutionized the way astronomers classify stars. Her mother Mary ignited her interest in astronomy by stargazing with her through a trapdoor in the roof where they had built a small observatory. Her mother encouraged her to study science and math in college. Annie was later hired to work with the Harvard computers creating the first Henry Draper Catalogue of the stars.
As part of her work at Harvard, Cannon created a stellar classification system based on stellar temperature. This became known as the Harvard spectral classification system and a modified version of it is still used today. Cannon’s system expanded upon and greatly simplified the work of other computers in the group (Williamina Flemming and Antonia Maury). Stars are classified as OBAFGKM by their temperature which correlates with color and a number determined by the star’s absorption spectrum (which indicates composition). Our Sun is a G2 star. In the modern system an additional roman numeral is used to indicate the luminocity or brigtness of the star, our sun is a G2V.
She earned a doctorate in astronomy in 1921 and continued to work in the field for around 40 years. It was thought by some that severe hearing loss from a childhood illness contributed to her ability to focus intently on her classifications.
In addition to her scientific work, Cannon was a strong advocate for women’s voting rights.
Source: U.S. Department of the Interior, National Park Service
