CECILIA PAYNE-GAPOSCHKIN BLUE PLAQUE AWARDED

Stuart Atkinson

A new blue plaque in London will soon commemorate the birthplace and achievements of one of the most important astronomers of the 20th century.

Her name was Cecilia Payne-Gaposchkin, and she was the first person to explain why stars shine.

Born in Wendover, England, Payne-Gaposchkin showed an early passion for learning. Studying at Cambridge, she was initially drawn to various sciences, but a lecture by astronomer Arthur Eddington inspired her to focus on astronomy and pursue it as a career. However, with opportunities for women in British science very limited, in 1923 she moved to the United States on a fellowship and found work at the Harvard College Observatory under its director Harlow Shapley.

Just two years later, her doctoral thesis, titled Stellar Atmospheres: A Contribution to the Observational Study of High Temperature in the Reversing Layers of Stars, changed astronomy forever. The astronomer Otto Struve later hailed it as “undoubtedly the most brilliant Ph.D. thesis ever written in astronomy.”

By analysing the spectra of stars, Payne-Gaposchkin discovered that the different spectral classes (O, B, A, F, G, K, M) correspond primarily to differences in the stars’ temperatures, not in their chemical composition. Her finding that stars are composed mainly of hydrogen and helium, rather than having a composition similar to Earth, represented a paradigm shift in stellar astronomy and laid the foundation for modern astrophysics.

The plaque, which will honour Payne-Gaposchkin’s life and achievements, will be placed at her teenage home at 70 Lansdowne Road in Notting Hill.

Other astronomers commemorated with a blue plaque include Frank Dyson; the scientific couple Walter Maunder and Annie Maunder; and Payne’s early inspiration, Eddington. However, Payne-Gaposchkin will be the first female astronomer to receive a blue plaque in her own right.

Stuart Atkinson