Williamina Fleming

Williamina Paton Stevens Fleming (May 15, 1857 – May 21, 1911) was a Scottish-born and American astronomer. During her career, she helped develop a common designation system for stars and cataloged thousands of stars and other astronomical phenomena. Among several career achievements that advanced astronomy Fleming is noted for her discovery of the Horsehead Nebula in 1888.^[1]

Biography

Williamina Stevens was born on May 15, 1857, to Mary and Robert Stevens; he a carver and gilder of Dundee, Scotland. There, in 1877, she married James Orr Fleming, an accountant and widower of Dundee. She worked as a teacher a short time before the couple emigrated to Boston, Massachusetts, USA, when she was 21.^[2] After she and her child were abandoned by James Fleming, she worked as a maid in the home of Professor Edward Charles Pickering, who was director of the Harvard College Observatory (HCO). The story was told that Pickering was often frustrated with the performance of the (all-male) "computers" at the observatory and, reportedly, would complain loudly: "My Scottish maid could do better!"^[3]

In 1881 Pickering hired Fleming to join the HCO and taught her how to analyze stellar spectra; she was the first of an all-women cadre of human "computers" created by Pickering at HCO.^[3] Soon she devised a system for classifying stars according to the relative amount of hydrogen observed in their spectra. (Stars showing hydrogen as the most abundant element were classified A; those of hydrogen as the second-most abundant element, B; and so on.) Later, Annie Jump Cannon developed an improved classification system based upon the surface temperature of stars.

Fleming contributed to the cataloging of stars that later were published as the Henry Draper Catalogue. In nine years' effort she cataloged more than 10,000 stars. During her career she discovered 59 gaseous nebulae, over 310 variable stars, and 10 novae. In 1907 she published a list of 222 variable stars she had discovered.

"Pickering's Harem," so-called, for the group of women computers at the Harvard College Observatory, who worked for the astronomer Edward Charles Pickering. The group included Harvard computer and astronomer Henrietta Swan Leavitt, Annie Jump Cannon, Williamina Fleming, and Antonia Maury.

In 1888, Fleming discovered the Horsehead Nebula on a telescope-photogrammetry plate made by astronomer W. H. Pickering, brother of E.C. Pickering; she described the bright nebula (later known as IC 434) as having "a semicircular indentation 5 minutes in diameter 30 minutes south of Zeta Orionis". Subsequent professional publications neglected to give credit to Fleming and W. H. Pickering for the discovery; the first Dreyer Index Catalogue omitted Fleming's name from the list of contributors having then discovered sky objects at Harvard, attributing the entire work merely to "Pickering"—presumably to mean E. C. Pickering, director of HCO. But by the time of the second Dreyer Index Catalogue, in 1908, Fleming and her colleagues at HCO were sufficiently well-known to receive proper credit for their discoveries; still, her first observation of the Horsehead Nebula was typically uncredited.

In 1886 Fleming was placed in charge of the dozens of women hired to compute mathematical classifications and edit the observatory's publications. In 1899, she was made Curator of Astronomical Photographs at Harvard, and in 1906, she was made an honorary member of the Royal Astronomical Society of London, the first American woman to be so honored.^[2] Soon after she was appointed honorary fellow in astronomy of Wellesley College. Shortly before her death the Astronomical Society of Mexico awarded her the Guadalupe Almendaro medal for her discovery of new stars. She published A Photographic Study of Variable Stars (1907). She published her discovery of white dwarfs (1910).^[2] Also she published Spectra and Photographic Magnitudes of Stars in Standard Regions (1911).

She died in Boston on May 21, 1911.^[2]

Honors

• The lunar crater Fleming was jointly named after her and (not closely related) Alexander Fleming.
• In 1906, she was made an honorary member of the Royal Astronomical Society of London, the first American woman to be so elected.^[2]

References

Notes

Birth and Marriage details from Scotland's People website http://www.scotlandspeople.gov.uk/ : Statutory Birth Record 282/02/0700; Statutory Marriage Record 282/03/0098

External links

• The discovery of early photographs of the Horsehead nebula, by Waldee & Hazen
• The Horsehead Nebula in the 19th Century, by Waldee (archived)
• Astrophysical Journal, vol. 34, p.314
• Bibliography from the Astronomical Society of the Pacific
• Project Continua: Biography of Williamina Paton Fleming Project Continua is a web-based multimedia resource dedicated to the creation and preservation of women’s intellectual history from the earliest surviving evidence into the 21st Century.

Obituaries

• MNRAS 72 (1912) 261