Quarter 3 Astronomer Project -- Henrietta Leavitt

Astronomer Project -- Henrietta Leavitt

Hennrietta Swan Leavitt was born on July 4, 1868 in Cambridge, Massachusetts to Congregational church minister George Roswell Leavitt and his wife Henrietta Swan (Kendrick). As a young girl, her family moved to Cleveland, Ohio. She attended Oberlin College and then graduated in 1892 from the Society for the Collegiate Instruction for Women, now known as Radcliffe College. In her senior year of college, Leavitt took her first astronomy course, earning an A- and cementing her interest in the subject. Pursuing the subject, she began graduate work at Harvard University, accepting a position as one of Edward Charles Pickering's computers in the Harvard College Observatory, working for $0.30 an hour. Pickering hired a number of women to measure and catalog the brightness of stars in the observatory's photographic plate collection. Tedious and menial work, Pickering sought to fill the role with women, thus earning his observatory the name "Pickering's Harem." Women in the early 1900's were not allowed to look through telescopes and were not given freedom to work theory. So, even though Henrietta Leavitt had the potential and the knowledge, she was not permitted to maximize her full possibilites.

She was chiefly in charge of cataloguing variable stars, stars whose brightness weakens and strengthens in a recognizable pattern. Studying the Magellanic Clouds, neighbor galaxies to the Milky Way, she discovered 1,777 variable stars. In 1908 she published her results in the Annals of the Astronomical Observatory of Harvard College, noting that a few of the variables showed a pattern: brighter ones appeared to have longer periods. After further investigation, Leavitt was able to classify certain stars as Cepheid variables, stars with a well defined relationship between luminosity and pulsation period.  "A straight line can be readily drawn among each of the two series of points corresponding to maxima and minima," Leavitt wrote of her study "thus showing that there is a simple relation between the brightness of the variable and their periods". Based on the period-luminosity variable, Leavitt determined Cepheid Scale Distances which have been used to determine absolute magnitude beyond the realm of parallax measurements. Prior to her discovery, it was not known that there were other galaxies outside of the Milky Way, because the distances were to great for parallax. Upon her discovery, Edwin Hubble detected the Andromeda Galaxy and the scientific community confirmed that the universe was much bigger than just the Milky Way.

Had Henrietta been allowed the opportunity to pursue her discovery further and had she not died of cancer in 1921, she surely would have contributed greatly to the measurement of the cosmos. Paperwork for her Nobel Prize began in 1924 without knowledge that she had died three years earlier. Hubble himself posits that Leavitt deserved a Nobel. Leavitt was a member of Phi Beta Kappa, 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. Her early passing was seen as a tragedy by her colleagues for reasons that went beyond her scientific achievements.