James Edward Keeler (September 10, 1857 – August 12, 1900) was an American astronomer.
|James Edward Keeler|
James Edward Keeler
September 10, 1857|
La Salle, Illinois
August 12, 1900 (aged 42)|
San Francisco, California
Rings of Saturn
|Awards||Henry Draper Medal (1899)|
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. His ashes were interred in a crypt at the base of the 31-inch Keeler Memorial telescope at the Allegheny Observatory.
His parents were William F. and Anna (née Dutton) Keeler. He had married in 1891 and left a widow and two children.
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, Keeler's contributions were brought to light. The second major gap in the A Ring, discovered by Voyager, was named the Keeler Gap in his honor.
|452 Hamiltonia||December 6, 1899|||
|(20958) A900 MA||June 29, 1900|||
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. 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.
His observations with the Lick Crossley telescope helped establish the importance of large optical reflecting telescopes, and expanded astronomers' understanding of nebulae. After his untimely death, his colleagues at Lick Observatory arranged for the publication of his photographs of nebulae and clusters in a special volume of the Lick Observatory publications.
Keeler discovered two minor planets, the Koronis asteroid 452 Hamiltonia in 1899, and the Mars-crosser asteroid (20958) A900 MA in 1900, which became a lost minor planet until its recovery 99 years later.
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".