On May 9, 1922, the International Astronomical Union formally adopted Annie Jump Cannon's stellar classification system, which with only minor changes, is still used today. A short excerpt from the text:
"Creating a Classification System
Soon into the project, a disagreement arose over how to classify the stars they were observing. One woman on the project, Antonia Maury (who was Draper’s niece) argued for a complex system, while another colleague, Williamina Fleming (who was Pickering’s chosen supervisor) wanted a simple system. It was Annie Jump Cannon who figured out a third system as a compromise. She divided stars into the spectral classes O, B, A, F, G, K, M—a system which is still taught to astronomy students today.
Annie’s first catalog of stellar spectra was published in 1901, and her career accelerated from that point on. She received a master’s degree in 1907 from Wellesley College, completing her studies from years earlier. In 1911, she became the Curator of Astronomical Photographs at Harvard, and three years later, she became an honorary member of the Royal Astronomical Society in the U.K. Despite these honors, Annie and her female colleagues were often criticized for working, rather than being housewives, and were often underpaid for long hours and tedious work.
Regardless of criticism, Annie persisted, and her career flourished. In 1921, she was among the first women to receive an honorary doctorate from a European university when the Dutch university Groningen University awarded her an honorary degree in math and astronomy. Four years later, she was awarded an honorary doctorate by Oxford – making her the first woman to receive an honorary doctorate of science from the elite university. Annie also joined the suffragist movement, advocating for women’s rights and, specifically, the extension of the right to vote; the right to vote for all women was finally won in 1928, eight years after the Nineteenth Amendment in 1920."