Cecilia Payne determines that stars are made largely of hydrogen and helium and that stars can be classified by temperature.
A photograph of Cecilia Payne at work.
Harvard College Observatory via Smithsonian Institution
Arianna Soldati & Brittney Borowiec, “Meet Cecilia Payne-Gaposchkin, Who Figured Out What the Universe Is Made Of,” Massive Science, 9 May 2020.
Amber Karlins, “Cecilia Payne-Gaposchkin – Astronomer,” The Heroine Collective, 4 February 2019.
Donovan Moore, “Cecilia Payne-Gaposchkin: Brief Life of a Breakthrough Astronomer, 1900-1979,” Harvard Magazine, May-June 2020.
Colleen Walsh, “Light Years Ahead: Star Analysts of Harvard College Observatory Struck Dava Sobel as Book-worthy History,” Harvard Gazette, 11 April 2017
Cecilia Payne, “Stellar Atmospheres: A Contribution to the Observational Study of High Temperature in the Reversing Layers of Stars,” Harvard Observatory Monographs, issue 1, 1925.
Dava Sobel, The Glass Universe: How the Ladies of the Harvard Observatory Took the Measure of the Stars, 2016