Women in Science, Medicine and Mathematics

Cecilia Payne-Gaposchkin

Cecilia Helena Payne was born in Wendover, England, on May 10, 1900. She was an astronomer who made the discovery that stars are mostly made of hydrogen and helium and can be classified according to temperature. She entered the University of Cambridge, in 1919. A lecture by the astronomer, Sir Arthur Eddington, who described his expedition to the island of Principe, off the western coast of Africa and confirmed Einstein's theory of relativity; inspired Cecilia to become an astronomer. Eddington encouraged Payne's pursuit of astrology but she felt there was more opportunities for women to study astrology in the US, than there was in Britain. So in 1923, she received a fellowship from the Harvard College Observatory, in Massachusetts; after corresponding with the observatory's director, Harlow Shapley. 

In her Ph.D thesis, Stellar Atmospheres, she used spectral lines of various elements and the work of Indian astrophysicist, Meghnad Saha, who had discovered an equation that connected the breaking up of elements in a star, to the temperature of a star; which showed that it was very likely that the composition and state of the stars could indeed affect their temperature. As has been aforementioned, Cecilia realized during her studies that stars were mostly made of hydrogen and helium. Her theory was disproved by fellow astronomer, Henry Norris Russell, who said stars were comprised of the same materials as the planet Earth is. In 1929, he revoked his original statement, admitting she had been right the whole time. Cecilia received her Ph.D in astronomy from Radcliffe College, since Harvard didn't give degrees to women. Her thesis was called "undoubtedly the most brilliant Ph.D thesis about astronomy".

Cecilia remained as a technical assistant to Shapley after completing her doctorate. Shapley had her drop her study of classifying stars and start studying photometry, which is the measurement of the brightness of stars and other celestial bodies (galaxies, nebulae & planets). This process also reveals many things about a star including: composition, temperature, density and so on. For her studies of photometry she used photographic plates, despite the fact more accurate brightness and measurements could be made with newly developed photoelectric equipment. She later wrote she wasted the last years of the decade because of this. However during this time she was able to continue working on the study of starlight, published her second book, Stars of High Luminosity, in 1930, which is also when she became interested in variable stars and nova (a class of exploding stars).

In 1933 she travelled to Europe to meet Russian astronomer, Boris Gerasimovich, who formerly worked at Harvard Observatory, with whom she planned to write a book about variable stars. In Gottingen, Germany she met, Sergey Gaposchkin, a Russian astronomer, who couldn't return to the Soviet Union because of his political beliefs. Cecilia was able to find him a job at the college. They married the following year and often collaborated for projects about variable stars. In 1938, she became a lecturer of astronomy, even though her name wasn't logged in the school's records until after WW2. 

In 1955, Cecilia Payne-Gaposchkin was made an official professor of Harvard, also becoming the head of the astronomy department. She retired in 1966 and passed away on Dec 7, 1979.

https://www.britannica.com/biography/Cecilia-Payne-Gaposchkin