On July 30, 1951, Annie Jump Cannon received an honorary doctorate from Oxford University — making her the first woman to receive an honorary science degree from Oxford. She was 87 years old. She had been classifying stars by hand since 1896.

Cannon was born in Delaware in 1863 and went partially deaf as a young adult, which may have contributed to her extraordinary powers of concentration and her ability to work for extended periods in isolation. She was hired by Edward Pickering at the Harvard Observatory as one of his "computers" — women paid to measure and catalog photographic plates at 25 cents an hour.

She developed, refined, and applied the OBAFGKM stellar classification system that became the Henry Draper Catalogue — the standard international system for classifying stars by temperature and spectral type, still in use today. She classified over 350,000 stars by hand. She could identify a star's type in three seconds by looking at its spectral image.

She was elected an honorary member of the Royal Astronomical Society in 1914, the fifth woman to be so honored, and awarded its Gold Medal in 1931. Harvard finally gave her an official faculty appointment in 1938 — forty-two years after she began working there.

She died in 1941, having classified more individual celestial objects than any person before her.