Expeditions and Discoveries Sponsored Exploration and Scientific Discovery in the Modern Age

Harvard College Observatory Expedition: Boyden Station, Arequipa, Peru, 1889–1927

The Harvard College Observatory (HCO) appointed Solon I. Bailey to find a site for a new observatory in the southern hemisphere. The goal of the new observatory would be to perform photographic surveys of the sky not visible from HCO’s northern latitude. In 1890, Bailey established the Boyden Station near Arequipa, Peru, and, between 1891 and 1927, astronomers used various telescopes and a meridian photometer to photograph stars in the southern sky and record their physical characteristics.

Women played a significant role in analyzing the data from Arequipa. Noteworthy among them was Henrietta Swan Leavitt who quantified the relationship between the brightness of Cepheid variable stars and their periods. Miss Leavitt’s period–luminosity relation became the yardstick for distance measurement to any galaxy containing Cepheid variables. Annie Jump Cannon classified stars by their spectral characteristics, and she was instrumental in creating the nine-volume Henry Draper Catalogue of visible stars in the entire sky.

Selected Manuscripts and Records in Expeditions and Discoveries



The following sources were used in writing this page.

  • Armstrong, Mabel. Women Astronomers: Reaching for the Stars. Marcola, Ore.: Stone Pine Press, 2008.
  • Bailey, Solon I. The History and Work of Harvard Observatory, 1839 to 1927: An Outline of the Origin, Development, and Researches of the Astronomical Observatory of Harvard College Together with Brief Biographies of Its Leading Members. New York: McGraw-Hill Book Co., 1931.
  • Johnson, George. Miss Leavitt’s Stars: The Untold Story of the Woman Who Discovered How to Measure the Universe. New York: W.W. Norton, 2005.
  • Jones, Bessie Zaban and Lyle Gifford Boyd. The Harvard College Observatory: The First Four Directorships, 1839–1919. Cambridge: Belknap Press of Harvard University Press, 1971.
  • Reed, Helen Leah. "Women’s Work at the Harvard Observatory." New England Magazine 6 (1892): 166–176.