Hertzsprung–Russell diagram
Not until 1922 did the International Astronomical Union (IAU) modify its classification system based on the work done by Maury and Hertzsprung, a formulation known as the Hertzsprung–Russell diagram. Astronomer Dorrit Hoffleit has presented scientific evidence to support the view that stellar morphology was held back by 30 years as a result of the failure to adopt Antonia Maury's stellar classification theory sooner.