Cecilia Payne-Gaposchkin was a British astronomer and one of the “hidden” women in science–women who contributed significantly to their field without appropriate recognition. One of her most notable discoveries, published as part of her doctoral thesis in 1925, was that stars are mostly composed of hydrogen and helium. Her analysis challenged the accepted belief that star compositions were similar to that of the Earth. While there was initial dissent, her discovery was confirmed in 1929. Throughout her career, Cecilia faced prejudice and bias as a woman in STEM. Although Cecilia studied at Harvard University, her doctorate was awarded through Radcliffe College because Harvard did not grant doctoral degrees to women at that time. She continued to work at Harvard as a ‘technical assistant’ in the astronomy department, where she was underpaid and assigned routine projects. It wasn’t until the Harvard observatory came under new leadership–nearly thirty years later–that her talent was appreciated. In 1956, Cecilia was appointed full professor at Harvard and later chairwoman of the astronomy department, becoming the first woman to lead a Harvard department. Image: Smithsonian GirlsInScience.ca/Sources/ #CeciliaPayneGaposchkin #WomenInAstronomy #Stars