Henrietta Leavitt

Next month, people will turn their (guarded) eyes to space to see the solar eclipse. This week, we look back in time to celebrate a woman who loved looking at space as well, astronomer Henrietta Leavitt (1868-1921). Henrietta was born in Cambridge, Massachusetts and fell in love with astronomy at the Society for Collegiate Instruction of Women (later Radcliffe College). A serious illness interrupted her studies and left her profoundly deaf, but she found that she didn’t need her hearing to contribute to science and explore the depths of outer space. Meticulously examining hundreds of pictures of stars at Harvard College Observatory (first as a volunteer and later for 30 cents an hour) she noticed that a certain type of star, Cepheid, changed brightness at a rate based on their intrinsic properties including mass, density, and surface brightness (not just differences in how we observe them). This observation allowed her to develop the Cepheid variable period-luminosity relationship (also known as Leavitt’s law). This relationship allowed scientists to calculate distances to distant galaxies and proved vital to the work of many of the more “famous” astronomers including Edwin Hubble, who used Leavitt’s law to help show the universe is expanding.

Additionally, Henrietta developed and curated the Harvard Standard, a photographic measurement standard that orders stars based on their brightness. Because of her gender, Henrietta was considered a mere “computer” and wasn’t given the freedom to pursue research on other topics that interested her, but neither sexism nor deafness could keep her from contributing to science as fully as she could. A Swedish scientist attempted to nominate her for the 1926 Nobel Prize in Physics, only to learn that she had died of cancer several years earlier. She did receive other honors, however, including membership in the American Association for the Advancement of Science. Additionally, an asteroid and a moon crater are named after her in honor to all of the deaf scientists who have contributed to astronomy.