James Edward Keeler (September 10, 1857 – August 12, 1900) was an American

astronomer An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, moons, comets and galaxies – in either ...

. He was an early observer of galaxies using photography, as well as the first to show observationally that the rings of Saturn do not rotate as a solid body.

Career and personal life

Keeler was born in La Salle Illinois, but grew up and spent the majority of his early life in

Mayport, Florida Mayport is a small community located between Naval Station Mayport and the St. Johns River in Jacksonville, Florida. It is part of the Jacksonville Beaches communities. The only public road to Mayport is State Road A1A, which crosses the St. Joh ...

near Jacksonville. His mother's father was a former

Governor of Connecticut The governor of Connecticut is the head of government of Connecticut, and the commander-in-chief of the U.S. state, state's Connecticut Military Department, military forces. The Governor (United States), governor has a duty to enforce state laws, ...

, Henry Dutton. Keeler worked at Lick Observatory beginning in 1888, but left after being appointed director of the

University of Pittsburgh The University of Pittsburgh (Pitt) is a public state-related research university in Pittsburgh, Pennsylvania. The university is composed of 17 undergraduate and graduate schools and colleges at its urban Pittsburgh campus, home to the univers ...

Allegheny Observatory The Allegheny Observatory is an American astronomical research institution, a part of the Department of Physics and Astronomy at the University of Pittsburgh. The facility is listed on the National Register of Historic Places (ref. # 79002157, ad ...

in 1891. He returned to Lick Observatory as its director in 1898, but died not long after in 1900. Keeler suffered from a heart weakness that went undiagnosed until shortly before his death. On the 12th of August he died from a sudden stroke. His ashes were interred in a crypt at the base of the 31-inch Keeler Memorial telescope at the

. Along with

George Hale George Ellery Hale (June 29, 1868 – February 21, 1938) was an American solar astronomer, best known for his discovery of magnetic fields in sunspots, and as the leader or key figure in the planning or construction of several world-lead ...

, Keeler founded and edited the ''

Astrophysical Journal ''The Astrophysical Journal'', often abbreviated ''ApJ'' (pronounced "ap jay") in references and speech, is a peer-reviewed scientific journal of astrophysics and astronomy, established in 1895 by American astronomers George Ellery Hale and ...

'', which remains a major journal of astronomy today. His parents were William F. and Anna (née Dutton) Keeler. He had married in 1891 and left a widow and two children.

Research

Keeler was the first to observe the gap in

Saturn's rings The rings of Saturn are the most extensive ring system of any planet in the Solar System. They consist of countless small particles, ranging in size from micrometers to meters, that orbit around Saturn. The ring particles are made almost entire ...

now known as the

Encke Gap The rings of Saturn are the most extensive ring system of any planet in the Solar System. They consist of countless small particles, ranging in size from micrometers to meters, that orbit around Saturn. The ring particles are made almost entirel ...

, 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 The rings of Saturn are the most extensive ring system of any planet in the Solar System. They consist of countless small particles, ranging in size from micrometers to meters, that orbit around Saturn. The ring particles are made almost entirel ...

, Keeler's contributions were brought to light. The second major gap in the

, discovered by '' Voyager'', was named the

Keeler Gap The rings of Saturn are the most extensive ring system of any planet in the Solar System. They consist of countless small particles, ranging in size from micrometers to meters, that orbit around Saturn. The ring particles are made almost ent ...

in his honor. In 1895, his spectroscopic study of the

rings of Saturn The rings of Saturn are the most extensive ring system of any planet in the Solar System. They consist of countless small particles, ranging in size from micrometers to meters, that orbit around Saturn. The ring particles are made almost entir ...

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 James Clerk Maxwell (13 June 1831 – 5 November 1879) was a Scottish mathematician and scientist responsible for the classical theory of electromagnetic radiation, which was the first theory to describe electricity, magnetism and li ...

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

. His observations with the Lick

Crossley telescope The Crossley telescope is a reflecting telescope located at Lick Observatory in the U.S. state of California. It was used between 1895 to 2010, and was donated to the observatory by Edward Crossley, its namesake. It was the largest glass refle ...

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 planet According to the International Astronomical Union (IAU), a minor planet is an astronomical object in direct orbit around the Sun that is exclusively classified as neither a planet nor a comet. Before 2006, the IAU officially used the term ''mino ...

s, the Koronis asteroid

452 Hamiltonia Hamiltonia (minor planet designation: 452 Hamiltonia) is an asteroid. It was discovered by James Edward Keeler on 6 December 1899, but was then lost until 1981. Its provisional name was 1899 FD. The asteroid is named for Mount Hamilton (Californ ...

in 1899, and the

Mars-crosser A Mars-crossing asteroid (MCA, also Mars-crosser, MC) is an asteroid whose orbit crosses that of Mars. Some Mars-crossers numbered below 100000 are listed here. They include the two numbered Mars trojans 5261 Eureka and . Many databases, for in ...

asteroid in 1900, which became a

lost minor planet A minor planet is "lost" when today's observers cannot find it, because its location is too uncertain to target observations. This happens if the orbital elements of a minor planet are not known accurately enough, typically because the observat ...

until its recovery 99 years later. After the discovery of pulsars in 1967, optical images of the Crab Nebula taken by Keeler in 1899 were used to determine the proper motion of the

Crab Pulsar The Crab Pulsar (PSR B0531+21) is a relatively young neutron star. The star is the central star in the Crab Nebula, a remnant of the supernova SN 1054, which was widely observed on Earth in the year 1054.

Honors and legacy

Keeler was awarded the

Henry Draper Medal The Henry Draper Medal is awarded every 4 years by the United States National Academy of Sciences "for investigations in astronomical physics". Named after Henry Draper, the medal is awarded with a gift of USD $15,000. The medal was established ...

from the National Academy of Sciences in 1899. In 1900 he was elected president of the Astronomical Society of the Pacific. In 1880, Allegheny Observatory director

Samuel Pierpont Langley Samuel Pierpont Langley (August 22, 1834 – February 27, 1906) was an American aviation pioneer, astronomer and physicist who invented the bolometer. He was the third secretary of the Smithsonian Institution and a professor of astronomy a ...

, 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 The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...

's radiation was selectively absorbed by the

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...

'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 The rings of Saturn are the most extensive ring system of any planet in the Solar System. They consist of countless small particles, ranging in size from micrometers to meters, that orbit around Saturn. The ring particles are made almost ent ...

in Saturn's rings, the Martian crater '' Keeler'', the lunar crater '' Keeler'', as well as the asteroid

2261 Keeler 61 may refer to: * 61 (number) * one of the years 61 BC, AD 61, 1961, 2061 * In some countries, a slang name for the Cyrillic letter Ы * ''61*'', a 2001 American sports drama film * "Sixty One", a song by Karma to Burn from the album ''Mountain Cz ...

, are named in his honor.

References

External links

* * * *
National Academy of Sciences Biographical Memoir
{{DEFAULTSORT:Keeler, James Edward 1857 births 1900 deaths 19th-century American astronomers American astrophysicists Discoverers of asteroids Heidelberg University alumni Lick Observatory University of Pittsburgh faculty