Henrietta Leavitt was born in Cambridge, Massachusetts in 1868. When she was young she moved to Cleveland, Ohio. She then attended Oberlin College and Radcliffe College, formerly known as the Society for the Collegiate Instruction of Women. During Leavitt’s senior year was when she discovered her passion for astronomy. However, she experienced a serious setback after college when she contracted a serious illness and became severely deaf. Because of that she spent several years at home, but did not ever stop thinking about astronomy.
In 1895, after spending three years at home, she started volunteering at the Harvard College Observatory. After seven years of hard work she was appointed to be a member of permanent staff, by director Charles Pickering. She became the head of the photographic photometry department, which studied images of stars to determine their magnitude. However, Pickering did not like his women employees to do work with theoretical endeavors, so in her position as the head of the department she mainly cleaned telescopes. During her career Leavitt discovered more than 2,400 variable stars during her career-- these are stars that change from bright to dim back to bright fairly regularly. Her most important contribution then, unsurprisingly, came from the field of variable stars. She discovered the cepheid variable period-luminosity relationhsip in 1908, from studying the Cepheid variables in the Small Magellanic Clouds. The basis of this is that there is a direct correlation between how bright a star is and how long it takes from a star to go from bright to dim. This relationship aided countless other astronomers’ discoveries, such as Edwin Hubble, Harlow Shapley, and Ejnar Hertzsprung.
She also, related to her work as the head of the photographic photometry department, created a standard of photographic measurements. She did this too by using the “north polar sequence” as a gauge for brightness of stars. They were accepted by the International Committee of Photographic Magnitudes in 1913, and then later renamed the Harvard Standard. In order to create this standard she used almost 300 plates and 13 telescopes, along with logarithmic equations to order the stars into 17 magnitudes of brightness. She continually improved and enlarged this work throughout her entire life, refining her standard.
However, Leavitt was not given the freedoms she desired. She was not allowed to pursue the topics of study she desired, but instead was assigned to what the observatory allowed. This was because of the prejudices of the day-- women were not given the opportunities that men were, so her true intellect was not used to its fullest. She was incredibly bright, as is remembered, because a colleague at the observatory remembers her as “possessing the best mind at the Observatory.” However, because of the limited rights of women in the 1800s, her full aptitude was not acknowledged. Her intellect is much more appreciated now, with a modern astronomer naming her as “the most brilliant woman at Harvard.” She continued working and pursuing her dreams at the Observatory until her death from cancer on December 21, 1921.
