James Edward Keeler

Infobox Scientist
name = James Edward Keeler
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caption = James Edward Keeler
birth_date = September 10 1857
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death_date = August 12 1900
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nationality = United States
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field = astronomy
work_institutions = Lick Observatory Allegheny Observatory
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known_for = Astrophysical Journal Rings of Saturn
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prizes = Henry Draper Medal in 1899
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James Edward Keeler (September 10 1857 – August 12 1900) was an American astronomer.

Career

Keeler worked at Lick Observatory beginning in 1888, but left after being appointed director of the University of Pittsburgh's Allegheny Observatory in 1891. He returned to Lick Observatory as its director in 1898, but died not long after in 1900. He had married in 1891 and left a widow and two children. His ashes were interred in a crypt at the base of the 31-inch Keeler Memorial telescope at the Allegheny Observatory.

Along with George Hale, Keeler founded and edited the "Astrophysical Journal", which remains a major journal of astronomy today.

Research

Keeler was the first to observe the gap in Saturn's rings now known as the Encke Gap, using the 36-inch refractor at Lick Observatory on 7 January 1888. After this feature had been named for Johann Encke, who had observed a much broader variation in the brightness of the A Ring, [David M. Harland, "Mission to Saturn: Cassini and the Huygens Probe", Chichester: Praxis Publishing, 2002.] Keeler's contributions were brought to light. [D. E. Osterbrock and D. P. Cruikshank, "J. E. Keeler's discovery of a gap in the outer part of the A Ring", "Icarus" 53, 165-173 (1983)] The second major gap in the A Ring, discovered by "Voyager", was named the Keeler Gap in his honor.

In 1895, his spectroscopic study of the rings of Saturn revealed that different parts of the rings reflect light with different Doppler shifts, due to their different rates of orbit around Saturn. [J. E. Keeler, "A spectroscopic proof of the meteoric constitution of Saturn's rings", "Astrophysical Journal" 1, 416-427 (1895)] This was the first observational confirmation of the theory of James Clerk Maxwell that the rings are made up of countless small objects, each orbiting Saturn at its own rate. These observations were made with a spectrograph attached to the 13-inch Fitz-Clark refracting telescope at Allegheny Observatory.

Keeler discovered two asteroids, one in 1899 and one in 1900, although the second was lost and only recovered about 100 years later.

Legacy

He won the Henry Draper Medal in 1899.

In 1880, Allegheny Observatory director Samuel Pierpont Langley, accompanied by Keeler and others, went on a scientific expedition to the summit of Mount Whitney. The purpose of the expedition was to study how the Sun's radiation was selectively absorbed by the Earth's atmosphere, comparing the results at high altitude with those found at lower levels. As a result of the expedition, a 14,240-ft. peak near Mount Whitney was named the "Keeler Needle".

In addition to the Keeler Gap in Saturn's rings, craters on Mars and the Moon are named in his honor, as is the asteroid 2261 Keeler.

References

External links

* cite journal
author = Campbell, W. W.
title = James Edward Keeler
journal = ApJ
month = November | year = 1900
volume = 12
pages = 239–253
doi = 10.1086/140764
url = http://articles.adsabs.harvard.edu//full/seri/ApJ../0012//0000239.000.html "obituary, includes extensive list of published writings"
* cite journal
author = H. H. T.
title = List of Fellows and Associates deceased during the past year
journal = Monthly Notices of the Royal Astronomical Society
month = February | year = 1901
volume = 61
pages = 197–199
url = http://articles.adsabs.harvard.edu//full/seri/MNRAS/0061//0000197.000.html