{{Short description|American astronomer (1857–1900)}} {{Infobox scientist |name = James Edward Keeler |image = Keeler James.jpg |image_size = 150px |caption = James Edward Keeler |birth_date = {{birth date|1857|9|10}} |birth_place = [[La Salle, Illinois]] |death_date = {{death date and age|1900|8|12|1857|9|10}} |death_place = [[San Francisco, California]] |residence = |citizenship = |ethnicity = |field = [[Astronomy]] |work_institutions = [[Lick Observatory]]<br />[[Allegheny Observatory]] |alma_mater = |doctoral_advisor = |doctoral_students = |known_for = [[Astrophysical Journal]]<br />[[Rings of Saturn]]<br />[[astrophotography]] |influences = |influenced = |prizes = [[Henry Draper Medal]] (1899) |religion = |footnotes = |signature = }}

'''James Edward Keeler''' (September 10, 1857 – August 12, 1900) was an American [[astronomer]]. 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 (Jacksonville)|Mayport, Florida]] near Jacksonville. His mother's father was a former [[Governor of Connecticut]], [[Henry Dutton (politician)|Henry Dutton]].

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. 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 Allegheny Observatory.<ref>See "''Biographical Memoir''", National Academy of Sciences</ref>

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

His parents were William F. and Anna (née Dutton) Keeler.<ref>{{cite book |title=The Biographical Encyclopedia of Astronomers |last=Hockey |first=Thomas |date=2009 |publisher=[[Springer Publishing]] |isbn=978-0-387-31022-0 |access-date=August 22, 2012 |url=http://www.springerreference.com/docs/html/chapterdbid/58748.html}}</ref> 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]] now known as the [[Encke Gap]], using the [[James Lick telescope|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 [[Rings of Saturn#A Ring|A Ring]],<ref>{{cite book |title=Mission to Saturn: Cassini and the Huygens Probe |last=Harland |first=David M. |date=2002 |publisher=Praxis Publishing |location=Chichester |isbn=978-1-85233-656-1 |url=https://archive.org/details/missiontosaturnc00harl |url-access=registration }}</ref> Keeler's contributions were brought to light.<ref>{{cite journal |last=Osterbrock |first=D. E. |author2=Cruikshank, D. P. |date=1983 |title=J. E. Keeler's discovery of a gap in the outer part of the A Ring |journal=[[Icarus (journal)|Icarus]] |volume=53 |issue= 2|pages=165–173 |doi=10.1016/0019-1035(83)90139-2 |bibcode=1983Icar...53..165O}}</ref> The second major gap in the [[Rings of Saturn#A Ring|A Ring]], discovered by ''[[Voyager program|Voyager]]'', was named the [[Rings of Saturn#Keeler Gap|Keeler Gap]] in his honor.

{| class="wikitable floatright" style="font-size: 0.9em; width: 270px;" |+ [[Minor planet]]s discovered: 2<ref name="MPC-Discoverers" /> |- | [[452 Hamiltonia]] || December 6, 1899 || <ref name="MPC-Hamiltonia" /><ref name="lcdb-Hamiltonia" /> |- | {{mp|(20958) A900 MA}} || June 29, 1900 || <ref name="MPC-20958" /> |}

In 1895, his spectroscopic study of the rings of Saturn revealed that different parts of the rings reflect light with different [[Doppler effect|Doppler shifts]], due to their different [[Kepler's laws of planetary motion|rates of orbit]] around Saturn.<ref>{{cite journal |last=Keeler |first=J. E. |date=1895 |title=A spectroscopic proof of the meteoric constitution of Saturn's rings |journal=[[Astrophysical Journal]] |volume=1 |pages=416–427 |doi=10.1086/140074 |bibcode=1895ApJ.....1..416K|s2cid=4032782 }}</ref> 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.<ref>{{cite journal |last=Keeler |first=J. E. |date=1908 |title=Photographs of Nebulae and Clusters made with the Crossley reflector|journal=Publications of the Lick Observatory |volume=8 |pages=1 |bibcode=1908PLicO...8....1K }}</ref>

Keeler discovered two [[minor planet]]s, the [[Koronis family|Koronis]] asteroid [[452 Hamiltonia]] in 1899, and the [[Mars-crosser]] asteroid {{mp|(20958) A900 MA}} in 1900, which became a [[lost minor planet]] until its recovery 99 years later.<ref name="MPC-20958" />

After the discovery of [[pulsar]]s in 1967, optical images of the [[Crab Nebula]] taken by Keeler in 1899 were used to determine the proper motion of the [[Crab Pulsar]].<ref name="Wyckoff, S. & Murray, C. A.">{{cite journal|title=Proper motion of the Crab pulsar |journal=Monthly Notices of the Royal Astronomical Society|volume=180|issue=4|pages=717–729|bibcode=1977MNRAS.180..717W |last1=Wyckoff |first1=S. |last2=Murray|first2=C. A.|year=1977|doi=10.1093/mnras/180.4.717|doi-access=free}}</ref>

== Honors and legacy ==

Keeler was awarded the [[Henry Draper Medal]] from the [[United States National Academy of Sciences|National Academy of Sciences]] in 1899.<ref name="Draper" /> In 1900 he was elected president of the [[Astronomical Society of the Pacific]].

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, the Martian crater ''[[Keeler (Martian crater)|Keeler]]'', the lunar crater ''[[Keeler (lunar crater)|Keeler]]'', as well as the asteroid [[2261 Keeler]], are named in his honor.<ref name="springer-Keeler" />

== References == <references>

<ref name="MPC-Discoverers">{{cite web |title = Minor Planet Discoverers (by number) |work = Minor Planet Center |url = http://www.minorplanetcenter.net/iau/lists/MPDiscsNum.html |date = 23 May 2016 |access-date = 21 June 2016}}</ref>

<ref name="MPC-Hamiltonia">{{cite web |title = 452 Hamiltonia (1899 FD) |work = Minor Planet Center |url = http://www.minorplanetcenter.net/db_search/show_object?object_id=452 |access-date = 21 June 2016}}</ref>

<ref name="lcdb-Hamiltonia">{{cite web |title = LCDB Data for (452) Hamiltonia |publisher = Asteroid Lightcurve Database (LCDB) |url = http://www.minorplanet.info/PHP/GenerateALCDEFPage_Local.php?AstInfo=452%7CHamiltonia |access-date = 21 June 2016 |archive-date = 5 March 2017 |archive-url = https://web.archive.org/web/20170305032451/http://www.minorplanet.info/PHP/GenerateALCDEFPage_Local.php?AstInfo=452%7CHamiltonia |url-status = dead }}</ref>

<ref name="MPC-20958">{{cite web |title = 20958 (A900 MA) |work = Minor Planet Center |url = http://www.minorplanetcenter.net/db_search/show_object?object_id=20958 |access-date = 21 June 2016}}</ref>

<ref name="Draper">{{cite web |title=Henry Draper Medal |url=http://www.nasonline.org/about-nas/awards/henry-draper-medal.html |publisher=[[National Academy of Sciences]] |access-date=19 February 2011 |url-status=dead |archive-url=https://web.archive.org/web/20130126003930/http://www.nasonline.org/about-nas/awards/henry-draper-medal.html |archive-date=26 January 2013 }}</ref>

<ref name="springer-Keeler">{{cite book |title = Dictionary of Minor Planet Names – (2261) Keeler |last = Schmadel | first = Lutz D. |publisher = Springer Berlin Heidelberg |page = 184 |date = 2007 |isbn = 978-3-540-00238-3 |doi = 10.1007/978-3-540-29925-7_2262 |chapter = (2261) Keeler }}</ref>

</references> <!-- end of reflist -->

== External links == * {{Gutenberg author | id=38290| name=James Edward Keeler}} * {{Internet Archive author |sname=James Edward Keeler}} * {{cite journal | author = Campbell, W. W. | title = James Edward Keeler | journal = [[Astrophysical Journal]] |date=November 1900 | volume = 12 | pages = 239–253 | doi = 10.1086/140764 | bibcode=1900ApJ....12..239C | doi-access = free }} * {{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]] |date=February 1901 | volume = 61 | issue = 4 | pages = 197–199 | bibcode = 1901MNRAS..61..197. | doi = 10.1093/mnras/61.4.197 | doi-access = free }} * [http://www.nasonline.org/publications/biographical-memoirs/memoir-pdfs/keeler-j-e.pdf National Academy of Sciences Biographical Memoir]

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{{DEFAULTSORT:Keeler, James Edward}} [[Category:1857 births]] [[Category:1900 deaths]] [[Category:19th-century American astronomers]] [[Category:American astrophysicists]] [[Category:Discoverers of asteroids]] [[Category:Heidelberg University alumni]] [[Category:Lick Observatory]] [[Category:University of Pittsburgh faculty]]