[10] She was a descendant of Deacon John Leavitt, an English Puritan tailor, who settled in the Massachusetts Bay Colony in the early seventeenth century.

[5] At Oberlin and Harvard, Leavitt studied a broad curriculum that included Latin and classical Greek, fine arts, philosophy, analytic geometry, and calculus.

Leavitt left the observatory to make two trips to Europe and completed a stint as an art assistant at Beloit College in Wisconsin.

[19] Pickering assigned Leavitt to study variable stars of the Small and Large Magellanic Clouds, as recorded on photographic plates taken with the Bruce Astrograph of the Boyden Station of the Harvard Observatory in Arequipa, Peru.

In 1908, Leavitt published the results of her studies in the Annals of the Astronomical Observatory of Harvard College, noting that the brighter variables had the longer period.

[7] In a 1912 paper, Leavitt examined the relationship between the periods and the brightness of a sample of 25 of the Cepheid variables in the Small Magellanic Cloud.

Leavitt also developed, and continued to refine, the Harvard Standard for photographic measurements, a logarithmic scale that orders stars by brightness greater than 17 magnitudes.

She initially analyzed 299 plates from 13 telescopes to construct her scale, which was accepted by the International Committee of Photographic Magnitudes in 1913.

[6]: 89 According to science writer Jeremy Bernstein, "variable stars had been of interest for years, but when she was studying those plates, I doubt Pickering thought she would make a significant discovery—one that would eventually change astronomy.

[4] The accomplishments of Edwin Hubble, the American astronomer who established that the universe is expanding, also were made possible by Leavitt's groundbreaking research.

[25] Mathematician Gösta Mittag-Leffler, a member of the Swedish Academy of Sciences, tried to nominate her for that prize in 1925, only to learn that she had died of cancer three years earlier.

Even greater distances can now be measured by using the theoretical maximum mass of white dwarfs calculated by Subrahmanyan Chandrasekhar.

[6]: 90 Anna Von Mertens designed a book-based work of art, Attention Is Discovery: The Life and Legacy of Henrietta Leavitt.

[34] Lauren Gunderson wrote a 2015 play, Silent Sky, which followed Leavitt's journey from her acceptance at Harvard to her death.

[35] Theo Strassell wrote a play, The Troubling Things We Do, an absurdist piece that details the life of Henrietta Leavitt, among other scientists from her era.

[36] Dava Sobel's book The Glass Universe chronicles the work of the women analyzing images taken of the stars at the Harvard College Observatory.

[37] The BBC included Leavitt in their Missed Genius series designed to celebrate individuals from diverse backgrounds who have had a profound effect on our world.