Williamina P. Fleming

Williamina moved to the U.S. in 1878 and started out working as a housekeeper for Edward C. Pickering, the director of the Harvard College Observatory. In 1881 he promoted her to join the team of Women Astronomical Computers, who studied glass plate photographs of the night sky. 

Over her 30-year career, she made many amazing discoveries.  She documented and studied over 10,000 stars, discovered 310 stars that change brightness (called variable stars), 10 novae (exploding stars), and 52 nebulae (clouds of gas and dust in space), including the famous Horsehead Nebula. 

Williamina became one of the most highly recognized and honored woman astronomers of her time. She joined important science groups like the Astronomical Society of America and the Astronomical Society of France. In 1893, she was even invited by the Congress of Astronomy and Astrophysics to speak at Chicago’s Columbian Exposition, also known as the World’s Fair. She also became an Honorary Fellow at Wellesley College and, in 1906, was the first American woman elected as an honorary member of the British Royal Astronomical Society. Just before she died, she received a gold medal from the Astronomical Society of Mexico for her discovery of new stars.

She also managed the Henry Draper Memorial, a project that took pictures of stars and studied their light (or spectra). The system she helped create to organize stars, called the Harvard classification system, is still used by astronomers today. She also organized the regular publication of the Annals of the Harvard College Observatory.

Until her passing in 1911, Williamina led and mentored the Women Astronomical Computers, who worked on studying the glass plate photographs.