1900 - 1979

Composition of the Sun and stars

Do you know the composition of the Sun? Thanks to Cecilia Payne-Gaposchkin, we know that hydrogen and helium constitute the bast majority of the composition of the Sun and other stars in our universe.

More than 20 years before Cambridge University granted degrees for women, Cecilia studied there and discovered her love for the stars. Later, embracing her curiosity, Cecilia moved to the College Observatory at Harvard in 1923, where she was granted a scholarship to encourage women to study science.

Only two years later, Cecilia Payne-Gaposchkin earned a PhD in astronomy. Her dissertation, ‘Stellar Atmospheres, a contribution to the observational study of high temperature in the reversing layers of stars’, was described by astronomer Otto Struve as “the most brilliant PhD thesis written in astronomy”.

At the age of 25 years old, Cecilia had disproved the believed that the sun was made out of heavy elements. Instead, Payne-Gaposchkin described hydrogen and helium as the key elements in the composition of the stars, including our Sun. Additionally, she identified hydrogen as the most abundant element in the universe.

Cecilia’s findings on the composition of stars were revolutionary. However, she was recommended to not publish her findings. The same person who suggested her to not pursue dissemination of her research, published a few years later the same findings through alternative research. While this person cited her, he received all the credit.

Cecilia continued studying the universe, and together with her team, they made millions of observations on stars. She became the first female full-professor at Harvard’s faculty of Arts and Science, and subsequent first female head of department at Harvard.

Thanks to Cecilia Payne-Gaposchkin, now we know that the sun is not a planet in fire, but helium and hydrogen. Thus, next time you enjoy a sunny day, remember Cecilia Payne-Gaposchkin, the scientist who introduced us to the Sun in its true essence.

Written by: Enriqueta Vallejo-Yagüe.