Williamina Fleming

Williamina Fleming was a Scottish-American astronomer who classified stars, discovered the Horsehead Nebula, and helped establish Harvard College Observatory’s photographic stellar catalogues.

Harvard Computers: Women hired by Harvard College Observatory to perform astronomical calculations and analyze observational data. Fleming led this group, whose work made large-scale stellar classification possible.
Astronomical photography: The recording of celestial objects using photographic or digital imaging instruments. Photographic plates supplied the durable evidence Fleming examined and catalogued.
Horsehead Nebula: A dark nebula in Orion whose silhouette resembles a horse’s head against glowing gas. Fleming identified it on a photographic plate in 1888.
Pickering's Harem: A historical nickname for the women astronomers employed at Harvard College Observatory under Edward Pickering. Fleming became a leading member of the group, whose labor supported the observatory’s surveys.
Henry Draper Catalogue: A catalogue of stellar spectra compiled from astronomical photographs at Harvard College Observatory. Fleming’s classification work became a foundation for this landmark catalogue.
Stellar spectroscopy: The study of stars through the wavelengths and patterns in their emitted light. Fleming classified stars by comparing spectral features recorded on plates.
Fleming 1: A planetary nebula in the constellation Centaurus, named for its discoverer. Fleming discovered this nebula while examining Harvard Observatory photographs.
Edward Charles Pickering: An American astronomer who directed Harvard College Observatory from 1877 to 1919. Pickering hired Fleming and placed her in charge of photographic classification work.
Antonia Maury: An American astronomer who developed a detailed system for classifying stellar spectra. Maury extended the Harvard classification work that Fleming helped organize.
Stellar classification: The grouping of stars by observable properties, especially their spectra and temperatures. It describes the systematic task at the center of Fleming’s Harvard work.

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