Henrietta Swan Leavitt
Henrietta Swan Leavitt (/ˈlɛvɪt/; July 4, 1868 – December 12, 1921) was an American astronomer.
Henrietta Swan Leavitt | |
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Born | July 4, 1868 Lancaster, Massachusetts, U.S. |
Died | December 12, 1921 Cambridge, Massachusetts, U.S. | (aged 53)
Alma mater | Radcliffe College, Oberlin College |
Known for | Leavitt's law: the period-luminosity relationship for Cepheid variables |
Scientific career | |
Fields | Astronomy |
Institutions | Harvard University |
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After she graduated from Radcliffe College, she worked at the Harvard College Observatory.
She examined photographic plates to measure and catalog the brightness of stars. She discovered the relation between the luminosity and the period of Cepheid variables.[3]
This gave astronomers with the first "standard candle" to measure the distance to faraway galaxies.[4][1]
She discovered the period-luminosity relationship for Cepheid variables. Her work allowed astronomers to measure distances up to about 20 million light years. As a result of this, it is now known that our own galaxy, the Milky Way, has a diameter of about 100,000 light years.
After Leavitt's death, Edwin Hubble established that the universe is expanding (see Hubble's law). He used Leavitt's period-luminosity relation, and the galactic spectral shifts first measured by Vesto Slipher at Lowell Observatory.
References
change- ↑ 1.0 1.1 Leavitt, Henrietta S.; Pickering, Edward C. (March 1912). "Periods of 25 Variable Stars in the Small Magellanic Cloud". Harvard College Observatory Circular. 173: 1–3. Bibcode:1912HarCi.173....1L.
- ↑ Malatesta, Kerri (April 13, 2010). "Delta Cephei". American Association of Variable Star Observers. Retrieved January 1, 2020.
- ↑ Johnson, George 2005. Miss Leavitt's stars: the untold story of the woman who discovered how to measure the universe. New York: W.W. Norton & Company. ISBN 978-0-393-05128-5
- ↑ Leavitt, Henrietta S. (1908). "1777 variables in the Magellanic Clouds". Annals of Harvard College Observatory. 60: 87–108. Bibcode:1908AnHar..60...87L.