Cecilia Payne Gaposchkin

Cecilia Payne Gaposchkin
Credit: Royal Astronomical Society
care of the Smithsonian Institution

Cecilia Payne Gaposchkin (1900 – 1979)

Cecilia Helena Payne was born in Wendover, England. In 1919 she won a scholarship to Newnham College in Cambridge University, where she studied botany, physics, and chemistry. While she was at Cambridge she went to a lecture by Arthur Eddington about his 1919 expedition to Africa to observe and photograph the stars near a solar eclipse to test Einstein’s general theory of relativity. This sparked her interest in astronomy.

Although she completed her studies and had been elected a Fellow of the Royal Astronomical Society in 1922, Cambridge did not grant degrees to women then and she realised that if she wanted to work in astronomy she would have to move to the United States. So in 1923 Cecilia left England to go to Harvard College Observatory, she became the second woman to join their graduate fellowship programme in astronomy for women and was the first person to earn a PhD in astronomy there.

Her thesis explained the composition of stars. Cecilia was able to accurately match the spectral classes of stars to their actual temperatures. She found that there was far more hydrogen and more helium in the Sun than there was in the Earth and so discovered that hydrogen was the main element in stars and, therefore, must also be the most abundant element in the Universe. At the time people thought that the Sun and the Earth were made up of the same amounts of all the elements and because her results were so different to this she was persuaded her not to state that conclusion. However, four years later, when the astronomer who reviewed her thesis (Henry Norris Russell) got the same results, he published the finding himself. So Cecilia is not fully credited with the discovery.

Cecilia stayed at Harvard and continued to study high luminosity stars and variable stars. However, she received little pay and held no official position until 1938 when she was given the title of “astronomer”. Then in 1954, when Donald Menzel took over as Director of the Harvard College Observatory, she became the first woman to be promoted to full professor and later on she became the first woman to head a department at Harvard.

Cecilia’s PhD is a turning point for women in astronomy, she was the first woman to be awarded a PhD from Harvard and this paved the way for women to enter the mainstream world of astronomy. She became an inspiration for many women who wanted to study science.