Henrietta
Swan Leavitt
, born on July 4, 1868, was the daughter of a Congregational
minister. She graduated from Radcliffe College in 1892. In 1895 she
accepted a position as a research assistant at Harvard College
Observatory. During her time at Harvard, she worked with Annie Jump
Cannon to measure the visual magnitudes of stars.
Leavitt's main research interest was photographic photometry, the problem of determining the brightness or magnitude of a star from a photographic image.
She also investigated variable stars in the Magellanic Clouds and discovered 1,777 new variable stars. Based on her observations, she concluded that variable stars are probably nearly the same distance from the Earth. Their periods are associated with their actual emission of light (determined by their mass, density, and surface brightness).
Henrietta Leavitt died in 1921.
References
Daintith, J., Mitchell, S., & Tootill, E. (1981). A Biographical Encyclopedia of Scientists. New York: Facts on File.
Kass-Simon, G., & Farnes, P. (1990). Women of Science: Righting the Record. Bloomington, IN: Indiana University Press.