What Are Stars Made Of? Cecilia Payne-Gaposchkin Discovered It First

British-American astrophysicist Cecilia Payne-Gaposchkin remained an unsung hero of the astronomy world. Discovering the composition of stars in the universe, Cecilia - who did not get her due - paved the path for women in STEM in more ways than one. Cecilia Payne-Gaposchkin, a name not as widely known as it should be, holds a pivotal place in our understanding of the universe. This astronomer, born in 1900, revolutionised our knowledge of stars by revealing their composition through her groundbreaking doctoral thesis in 1925 which was rejected at the time as it is said to have "contradicted the scientific wisdom at the time." There are many more contributions of Payne in the field of science and for women.

Who Was Cecilia Payne-Gaposchkin? 

Payne, who moved with her family to London for the education of her brother, was refused funding for her further education. Not letting her spirits down by this, Payne managed to secure a scholarship for her further education at Cambridge University in 1919. During her education at Cambridge, she participated in an expedition of observing and photographing stars near the solar eclipse for a test on Albert Einstein's Theory of Relativity that sparked her interest in the world of Astronomy at the age of just 19. As Payne successfully completed her education at Cambridge University, she was not awarded a degree due to her gender as Cambridge did not offer degrees to women up till 1948.

Realising the career restraints in the UK at the time compelling her to either pursue the path of a teacher or homemaker, she took the bold step to move to the United States where there was comparatively better exposure for women to pursue science. 

In 1923, Payne left England and moved to Harvard College Observatory after she was introduced to Harlow Shapley, the Director of Harvard College as he had just introduced the graduate program for astronomy. Following this, she became the second woman in the fellowship and became the first person to earn a PhD in astronomy from Radcliffe College of Harvard University.

Shapley, who always encouraged Payne to pursue the path of her dreams, urged her to prepare for a doctorial dissection during her PhD programme. She prepared a thesis in 1925 studying more than 3,00,000 variable stars and applying the ionization theory of Indian physicist Meghnad Saha to prove the abundance of Hydrogen (predominantly) and Helium presence in the atoms of the Milky Way.

Through this thesis, Cecila not only discovered what the universe was made of but also discovered the elements the Sun was made of and the similarity between Earth and the Sun. At the time when the thesis was presented, it was not recognised as it was met with scepticism as the scientific community simply couldn't reconcile the vast difference between the Earth's composition and that of stars but later a Russian-American astronomer Otto Struve described Cecilia's thesis as "the most brilliant PhD thesis ever written in astronomy."

Henry Norris Russell, an American astronomer, who is often credited for discovering the elements and compositions of the Sun are similar to the Earth, discovered this four years after Payne's thesis that was not published. Russell later realised Payne's pre-discovery and credited her in 1929 while publishing his findings. 

Payne who spent her life working in the field of science at Harvard, spent years working in less prestigious and low-paid research jobs. Director Shapley who always worked to make her position better managed to give her the title of "astronomer" only in 1938, decades after her PhD, while her work was not published in the Harvard catalogue until 1945. 

Donald Menzel who became the next Director of the Harvard College Observatory in 1954 appointed Payne in 1956 as the first full-time woman professor at Harvard and she later became the first woman to chair a department at Harvard paving a groundbreaking path for women in Harvard's science department and inspiring an entire generation of women to pursue science. 

While Payne-Gaposchkin's impact on astronomy is undeniable, her story also highlights the struggles faced by women in science during her era.