Annie Jump Cannon
||This article includes a list of references, but its sources remain unclear because it has insufficient inline citations. (November 2012)|
|Annie Jump Cannon|
Annie Jump Cannon
December 11, 1863|
|Died||April 13, 1941(aged 77)|
|Known for||stellar classification|
|Notable awards||Henry Draper Medal (1931)|
Annie Jump Cannon (December 11, 1863 - April 13, 1941) was an American astronomer whose cataloging work was instrumental in the development of contemporary stellar classification. With Edward C. Pickering, she is credited with the creation of the Harvard Classification Scheme, which was the first serious attempt to organize and classify stars based on their temperatures.
The daughter of shipbuilder and state senator Wilson Lee Cannon and his second wife, Mary Elizabeth Jump, Cannon grew up in Dover, Delaware. Cannon's mother had a childhood interest in star-gazing, and she passed that interest along to her daughter. Cannon had four older step-siblings from her father's first marriage, as well as two brothers, Robert and Wilson. Cannon never married but was happy to be an aunt to her brother's children.
At Wilmington Conference Academy, Cannon was a promising student, particularly in mathematics. In 1880, Cannon was sent to Wellesley College in Massachusetts, one of the top academic schools for women in the U.S. The cold winter climate in the area led to repeated infections, and in one instance Cannon was stricken with scarlet fever. As a result, she became almost completely deaf.
Cannon graduated with a degree in physics in 1884 and returned home. Uninterested in the limited career opportunities available to women, she grew bored and restless. Her partial hearing loss made socializing difficult, and she was generally older and better educated than most of the unmarried women in the area. She had made a trip to Europe in 1892 to photograph the solar eclipse, but returned with her situation little improved.
In 1894, Cannon's mother died and life in the home grew more difficult. She finally wrote to her former instructor at Wellesley, professor of physics and astronomy Sarah Frances Whiting, to see if there was a job opening. Whiting hired her as an assistant, which allowed Cannon to take graduate courses at the college in physics and astronomy. Whiting also inspired Cannon to learn about spectroscopy. Also during these years, Cannon developed her skills in the new art of photography.
In order to gain access to a better telescope, Cannon enrolled at Radcliffe Women's College at Harvard University, which had access to the Harvard College Observatory. In 1896, Edward C. Pickering hired Cannon as his assistant at the Observatory. By 1907, she had received a MA from Wellesley.
In 1896, Cannon became a member of Pickering’s Women, the women hired by Harvard Observatory director Pickering to complete the Henry Draper Catalogue mapping and defining every star in the sky to photographic magnitude of about 9.
Anna Draper, the widow of wealthy physician and amateur astronomer Henry Draper, set up a fund to support the work. Pickering made the Catalogue a long-term project to obtain the optical spectra of as many stars as possible and to index and classify stars by spectra. If making measurements was hard, the development of a reasonable classification was at least as difficult.
Not long after the work on the Draper Catalogue began, a disagreement developed as to how to classify the stars. Antonia Maury, Henry Draper's niece, insisted on a complex classification system while Williamina Fleming, who was overseeing the project for Pickering, wanted a much more simple, straightforward approach. Cannon negotiated a compromise: she started by examining the bright southern hemisphere stars. To these stars she applied a third system, a division of stars into the spectral classes O, B, A, F, G, K, M. Her scheme was based on the strength of the Balmer absorption lines. After absorption lines were understood in terms of stellar temperatures, her initial classification system was rearranged to avoid having to update star catalogues. The mnemonic of "Oh Be a Fine Girl, Kiss Me" has developed as a way to remember stellar classification. The female astronomers doing this groundbreaking work at the Observatory earned 25 cents per hour, which was less than what the secretaries at the university earned. 
Cannon’s work was theory-laced but simplified. Her observation of stars and stellar spectra was extraordinary. Her Draper Catalogue listed nearly 230,000 stars, all the work of a single observer. Cannon also published other catalogues of variable stars, including 300 that she personally discovered. Her career lasted more than 40 years, during which time women gained acceptance within the scientific community.
Cannon died April 13, 1941 after being named the William C. Bond astronomer at Harvard in 1938. She was also the only single female to win the Henry Draper Medal from the National Academy of Sciences, in 1931. (Martha P. Haynes shared her honor with a male colleague.)
Awards and honors
- 1925, the first honorary doctorate ever awarded to a woman by Oxford University
- 1929, listed as one of twelve "greatest living women" from the National League of Women Voters
- 1932, the Ellen Richards prize
- First woman elected an officer of the American Astronomical Society
- The lunar crater Cannon named after her
- Nicknamed "Census Taker of the Sky" for classifying 230,000 stellar bodies, more than any other person, male or female
- The Annie J. Cannon Award in Astronomy named in her honor; award has been awarded annually to a woman astronomer in North America since 1934
- Cannon Hall, a residence dormitory at the University of Delaware, named in her honor
- Reynolds, Moira Davison (2004). American women scientists: 23 inspiring biographies, 1900-2000. McFarland. p. 18. ISBN 9780786421619.
- "Annie Jump Cannon (1863-1941), sitting at desk". Smithsonian Institution Archives. Smithsonian Institution. Retrieved 11 July 2013.
- Shteynberg, Catherine. "Pickering's Women". Smithsonian Institution Archives. Smithsonian Institution. Retrieved 8 May 2009.
- "Star classification (stellar classification)". Astrophysical.org. Istituto Scientia. Retrieved 10 July 2013.
- Johnson, George (2005). Miss Leavitt's stars. W. W. Norton & Company, Incorporated. ISBN 0393328562.
- "Henry Draper Medal". National Academy of Sciences. Retrieved 19 February 2011.
- Greenstein, George (1993). "The ladies of Observatory Hill". American Scholar 62: 437–446.
- Nancy J. Veglahn, Women Scientists, 1991 in literature, Facts on File, ISBN 0-8160-2482-0
- Annie Jump Cannon audio talk with colleagues from 365DaysOfAstronomy.Org
- Wellesley College Astronomy Department: Annie Jump Cannon from Wellesley College
- Bibliography from the Astronomical Society of the Pacific