James Edward Keeler
James Edward Keeler (born September 10, 1857 in La Salle , Illinois ( United States ), † August 12, 1900 in San Francisco ) was an American astrophysicist . He dealt v. a. with planetary observation and spectroscopy .
Life
Between the ages of twelve and twenty, Keeler did not go to school, but continued to educate himself. Keeler studied from 1877 with the help of a benefactor at the Johns Hopkins University in Baltimore and graduated there in 1881. He became an assistant to Samuel Pierpoint Langley at the Alleghenny Observatory in Pennsylvania . Here he remained until 1886. He started working at the observatory with an expedition to the Rocky Mountains to the infrared radiation of the sun to measure.
Between 1883 and 1884 he stayed for further studies in Heidelberg and Berlin .
In 1886 Keeler went to the Lick Observatory on Mount Hamilton (which was not completed until 1888), where he had held the position of astronomer since 1888 . On June 1, 1891, he was appointed director of the Alleghenny Observatory and at the same time employed as a professor of astrophysics at the Western University of Pennsylvania . In 1898 he returned to the Lick Observatory as director.
James Edward Keeler died unexpectedly on August 12, 1900 in San Francisco.
plant
Keeler's specialty was spectroscopy .
His earliest work concerned the spectroscopic similarity between the stellar spectra and the Orion Nebula . In 1894 he succeeded in spectroscopic proof of the radial speed of planetary nebulae based on the red and blue shift. Its success is mainly due to its instrumentation; a grating spectroscope was available to him, which he combined with the 91 cm refractor of the Lick observatory. (see Gudrun Wolfschmidt , Milchstrasse, Nebel, Galaxien , 1995)
He also carried out planetary observations, e.g. B. that of Mars , although he could not confirm the observations of the so-called Mars channels that Schiaparelli believed he had found and which sparked so much speculation at the end of the 19th century. In 1895 he examined the rings of Saturn with the help of spectroscopic methods in order to determine their period of revolution . He found that the rings did not rotate uniformly and therefore could not be made of solid matter. He supported James Clerk Maxwell's assumption that the rings consisted of meteorites and dust. He was also the first to observe the Encke division of Saturn's rings in January 1888 .
In addition to his art of observation, Keeler was also able to construct and improve instruments. So he built an improved spectrograph that allowed the photographic recording of stellar spectral lines even with low brightness.
Keeler realized that most of the galaxies have a spiral shape.
Honors
- In 1892 he was elected to the American Academy of Arts and Sciences .
- In 1898 Keeler became a member of the Royal Astronomical Society in London .
- In 1900 Keeler was elected to the US National Academy of Sciences .
- In 1970 the lunar crater Keeler was named after him.
- In 1973 the Martian crater Keeler was named after him.
- In 1988 the asteroid (2261) Keeler was named after him.
Web links
- Publications by JE Keeler in the Astrophysics Data System
- Obituaries for JE Keeler in the Astrophysics Data System
Individual evidence
- ^ Lutz D. Schmadel : Dictionary of Minor Planet Names . Fifth Revised and Enlarged Edition. Ed .: Lutz D. Schmadel. 5th edition. Springer Verlag , Berlin , Heidelberg 2003, ISBN 978-3-540-29925-7 , pp. 184 (English, 992 pp., Link.springer.com [ONLINE; accessed November 2, 2017] Original title: Dictionary of Minor Planet Names . First edition: Springer Verlag, Berlin, Heidelberg 1992): “Named in memory of James Edward Keeler (1857–1900) ”
| personal data | |
|---|---|
| SURNAME | Keeler, James Edward |
| BRIEF DESCRIPTION | American astrophysicist |
| DATE OF BIRTH | September 10, 1857 |
| PLACE OF BIRTH | La Salle , Illinois ( USA ) |
| DATE OF DEATH | August 12, 1900 |
| Place of death | San Francisco |