The Harvard Computers

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Edward C. Pickering and the Computers in a group shot taken in May 1913. Image courtesy of the Harvard-Smithsonian Center for Astrophysics

Edward C. Pickering and the Computers in a group shot taken in May 1913.

Image courtesy of the Harvard-Smithsonian Center for Astrophysics


Before the days of Bill Gates and OS updates, the word “computer” was used (as far back as the 17th century) to describe a person who performs calculations. The latest episode of Shelf Life includes a segment about Henrietta Leavitt—an astronomer and human “computer” whose discoveries allowed researchers to determine cosmic distances. 

Leavitt was one of a group of about 80 women, known as “the Harvard Computers,” who worked at the Harvard Observatory at the turn of the century. The Computers were hired by the Observatory’s director, Edward Charles Pickering, to help catalog and analyze thousands of early photographs of the night sky.

This assembly of scientifically-minded women has a somewhat apocryphal origin story: that Pickering—frustrated with his assistant’s sloppy cataloging—fired the male staffer with the words, “Even my maid could do a better job.” He did, in fact, then hire his maid Williamina Fleming as the first of the female computers. Fleming, who had been a teacher before becoming a maid, made several lasting contributions to astronomy, discovering the famed Horsehead Nebula and helping to develop a temperature-based classification system for stars.

Prior to her work as a Computer, Fleming worked as an educator, as well as a maid.  Wikipedia / Harvard College Observatory

Prior to her work as a Computer, Fleming worked as an educator, as well as a maid. 

Wikipedia / Harvard College Observatory


The Computers worked six-day weeks and earned between 25 and 50 cents an hour.  Employed as technicians, their tasks included measuring the brightness of stars and analyzing spectra to determine the properties of celestial objects. Aside from their clerical bookkeeping, however, many of the women were fascinated with astronomy and made discoveries of great importance.

Annie Jump Cannon was hired by Pickering in 1896, but unlike some of her fellow Computers, she’d previously studied physics and astronomy at Wellesley and Radcliffe. Cannon classified hundreds of thousands of stars in her career and developed a standard stellar classification system that’s still in use today. She became the first woman elected as an officer to the American Astronomical Society and was the first woman to receive an honorary degree from the University of Oxford.

Annie Jump Cannon and Henrietta Leavitt ©HUP Cannon, Annie Jump, Harvard University Archives

Annie Jump Cannon and Henrietta Leavitt

©HUP Cannon, Annie Jump, Harvard University Archives


Today, Museum astrophysicist Ashley Pagnotta (featured in the latest Shelf Life episode visits the Harvard College Observatory at least once a year to look at glass plates of the night sky and revisit the data generated by the Harvard Computers. “I use the same plates that these women did,” says Pagnotta. “When I go through them, I come across ones that have their notations. That’s one of my favorite things about going to the plate stacks. These are women whom I’ve looked up to for a long time.”