Henrietta Swan Leavitt
Henrietta Swan Leavitt
Henrietta Swan Leavitt was an astronomer who worked at the Harvard College Observatory at the turn of the nineteenth and twentieth centuries.
Leavitt was born in in Lancaster, Massachusetts in 1868 and grew up in Cleveland, Ohio. She attended Oberlin College and later went to Radcliffe College, then called the Society for the Collegiate Instruction for Women and graduated with a bachelor’s degree in 1892.
In 1893, she was hired by Edward Charles Pickering, an astronomer and physicist and she started working under him at the Harvard College Observatory. Pickering actually hired about a dozen skilled women to work under him to process astronomical data and analyze stellar spectra. This staff of women came to be called the ‘Harvard Computers’, or more mockingly by the male-dominated scientific community as ‘Pickering’s Harem’. In the late nineteenth and early twentieth century, many other famous male scientists also practiced this process of hiring a bevy of subordinate females, who were seen as less threatening and were also cheaper. This is known as the ‘Harem effect’ in the history of science. Initially Leavitt worked as a volunteer as she had independent sources of income. So Pickering did not have to pay her at all. Later she was paid around $10.50 a week.
Leavitt was assigned the task of studying and cataloguing variable stars, whose luminosity varied with time. Leavitt discovered more than 2,400 variable stars and also found that these stars changed their brightness and dimness in a fairly regular pattern and there was a direct correlation between the time taken and the star’s luminosity. This led her to establish the cepheid variable period luminosity relationship. Leavitt could only work sporadically at Harvard as she suffered from an illness which made her increasingly deaf. In 1908 published her results in the Annals of the Astronomical Observatory of Harvard College. In 1921, she became the head of the stellar photographic photometry department at Harvard, which studied photo images of stars to determine their magnitude. Leavitt developed a standard of photographic measurement that was accepted by the International Committee of Photographic magnitudes as the ‘Harvard Standard’.
Leavitt did not get much recognition during her lifetime. She could not pursue her own topics of research and had to work on what Pickering assigned to her. Her discoveries, especially the period luminosity relationship later paved the way for the discoveries of other astronomers, particularly Edwin Hubble. In 1924, the Swedish Academy of Sciences tried to award her the Nobel Prize, but she had already dies of cancer three years earlier. Infact, Shapley, the new director of the observatory, tried to take credit for her work.
Leavitt was a member of the American Association of University Women, the American Astronomical and Astrophysical Society, the American Association for the Advancement of Science and an honorary member of the American Association of Variable Star Observers. The asteroid 5383 Leavitt and the lunar crater Leavitt were named in her honour.
