Henrietta Swan Leavitt

Henrietta Swan Leavitt ( born July 4, 1868 in Lancaster, Massachusetts, † December 12, 1921 in Cambridge, Massachusetts) was an American astronomer.

Life and work

For astronomy Leavitt interested already in college. Through illness, she was almost completely deaf. Nevertheless, at the Harvard College Observatory in 1895 she got a volunteer place, and seven years later she was offered a permanent job (for 30 cents an hour ). There observed and cataloged Leavitt variable stars, but in 1904 they could detect 172 variable stars in the large and 59 in the Small Magellanic Cloud. A year later, she reported 843 new variable stars in the Small Magellanic Cloud. 1912 Leavitt discovered the period-luminosity relation for Cepheids.

Ejnar Hertzsprung in 1913 succeeded then the determination of the distance of some Cepheids of the Milky Way, so the distance to all Cepheids could be calibrated. As in 1920 were discovered by Edwin Hubble Cepheids in other galaxies as in the Andromeda Galaxy, the first time distances between different galaxies could be determined. Prior to these discoveries could be expected only with distances up to 100 light years, then put far away as 10 million light- years no longer a problem

In all the years of observation of the night sky Leavitt was able to observe four novae and discover over 2400 new variable stars. They also developed a new photographic measurement technique that was in 1913 international recognition and is known as the Harvard standard.

Henrietta Swan Leavitt is considered a pioneer of science, and that's because she was not only one of the few and the first women in the higher sciences. She was a member of various compounds such as Phi Beta Kappa, the American Association of University Women, the American Astronomical and Astrophysical Society, the American Association for the Advancement of Science and an Honorary Member of the American Association of Variable Star Observers.

Henrietta Swan Leavitt died in 1921 from cancer. In her honor, the 1973 bear discovered asteroid ( 5383 ) and a lunar crater named. Unaware of her death was considering the Swedish mathematician Gösta Mittag-Leffler in 1925 to propose Leavitt for a Nobel Prize.

Writings

The messages are usually initially signed by Edward C. Pickering, Director of the Observatory, Leavitt and their contribution called it.

• New variable stars in Harvard map, nos. 3 and 6, Harvard College Observatory Circular 127, April 12, 1907 (English)
• 25 new variable stars in Harvard map, nos. 24, 36, and 42, Harvard College Observatory Circular 135, December 17, 1907 (English)
• 29 new variable stars near Nova Sagittarii, Harvard College Observatory Circular 141, July 22, 1908 ( English)
• 1777 variables in the Magellanic Clouds, Annals of Harvard College Observatory 60, 1908, pp. 87-108 (English)
• Adopted photographic magnitudes of 96 polar stars, Harvard College Observatory Circular 170, February 21, 1912, pp. 1-5 ( English)
• Periods of 25 variable stars in the Small Magellanic Cloud, Harvard College Observatory Circular 173, March 3, 1912, pp. 1-3 (English)
• The north polar sequence, Annals of Harvard College Observatory 71, 1917, pp. 47-232 (English)
• Standards of magnitude for the astrographic catalog, Annals of Harvard College Observatory 85, January 29, 1919, pp. 1-33 (English)