{{Short description|Main-belt asteroid}} {{For|the moon of Saturn|Prometheus (moon)}} {{Use dmy dates|date=October 2019}} {{Infobox planet | minorplanet = yes | name = 1809 Prometheus | background = #D6D6D6 | image = 001809-asteroid shape model (1809) Prometheus.png | image_scale = | caption = Shape model of Prometheus from its lightcurve | discovery_ref = <ref name="jpldata" /> | discovered = 24 September 1960 | discoverer = C. J. van Houten<br />I. van Houten-G.<br />T. Gehrels<br />{{small|(Palomar–Leiden survey)}} | discovery_site = Palomar Obs. | mpc_name = (1809) Prometheus | alt_names = 2522 P-L{{·}}{{mp|1943 EA|1}}<br />1955 SW{{·}}1955 VA<br />1965 UR | pronounced = {{IPAc-en|p|r|ə|ˈ|m|iː|θ|iː<!--[sic] - long /iː/ with -ευς-->|ə|s}}<ref>{{Cite encyclopedia |url=http://www.lexico.com/definition/Prometheus |archive-url=https://web.archive.org/web/20200320063552/https://www.lexico.com/definition/prometheus |url-status=dead |archive-date=20 March 2020 |title=Prometheus |dictionary=Lexico UK English Dictionary |publisher=Oxford University Press}}</ref> | adjective = Promethean, -ian {{IPAc-en|p|r|ə|ˈ|m|iː|θ|iː|ə|n}}<ref>{{Cite encyclopedia |url=http://www.lexico.com/definition/Promethean |archive-url=https://web.archive.org/web/20200320063559/https://www.lexico.com/definition/promethean |url-status=dead |archive-date=20 March 2020 |title=Promethean |dictionary=Lexico UK English Dictionary UK English Dictionary |publisher=Oxford University Press}}</ref> | named_after = Προμηθεύς ''Promētheys''<br />{{small|(Greek mythology)}}<ref name="springer" /> | mp_category = main-belt{{·}}{{small|(outer)}} | orbit_ref = <ref name="jpldata" /> | epoch = 4 September 2017 (JD 2458000.5) | uncertainty = 0 | observation_arc = 61.53 yr (22,473 days) | aphelion = 3.2256 AU | perihelion = 2.6245 AU | semimajor = 2.9251 AU | eccentricity = 0.1027 | period = 5.00 yr (1,827 days) | mean_anomaly = 163.57° | mean_motion = {{Deg2DMS|0.1970|sup=ms}} / day | inclination = 3.2585° | asc_node = 99.484° | arg_peri = 231.33° | dimensions = {{val|14.212|0.097}} km<ref name="Masiero-2014" /> | rotation = | albedo = {{val|0.126|0.010}}<ref name="Masiero-2014" /> | spectral_type = | abs_magnitude = 11.7<ref name="jpldata" /> }}
'''1809 Prometheus''' {{IPAc-en|p|r|ə|ˈ|m|iː|θ|iː|ə|s}} is an asteroid from the outer region of the asteroid belt, approximately 14 kilometers in diameter. Discovered during the Palomar–Leiden survey in 1960, it was given the provisional designation {{mp|2522 P-L}} and named after Prometheus from Greek mythology.<ref name="springer" />
== Orbit and classification ==
Prometheus orbits the Sun in the outer main-belt at a distance of 2.6–3.2 AU once every 5.00 years (1,827 days). Its orbit has an eccentricity of 0.10 and an inclination of 3° with respect to the ecliptic.<ref name="jpldata" />
== Discovery ==
It was discovered on 24 September 1960, by the Dutch astronomer couple Ingrid and Cornelis Johannes van Houten at Leiden, on photographic plates taken by Dutch–American astronomer Tom Gehrels at Palomar, California, in the United States.<ref name="MPC-Prometheus" /> On the same night, the team of astronomers discovered several other minor planets including 1810 Epimetheus.
Prometheus was first identified as {{mp|1943 EA|1}} at the Hungarian Konkoly Observatory in 1943. In 1955, its first used observation was taken at Goethe Link Observatory, when it was identified as {{mp|1955 SW}}, extending the body's observation arc by 5 years prior to its official discovery observation.<ref name="MPC-Prometheus" />
The survey designation "P-L" stands for ''Palomar–Leiden'', named after Palomar Observatory and Leiden Observatory, which collaborated on the fruitful Palomar–Leiden survey in the 1960s. Gehrels used Palomar's Samuel Oschin telescope (also known as the 48-inch Schmidt Telescope), and shipped the photographic plates to Ingrid and Cornelis van Houten at Leiden, where astrometry was carried out. The trio are credited with the discovery of several thousand minor planets.<ref name="MPC-discoverers" />
== Naming ==
This minor planet was named for Prometheus, a Titan from Greek mythology, who stole the fire from the gods. The name has also been given to a moon of Saturn, Prometheus (moon), discovered by the Voyager 1 spacecraft in 1980.<ref name="springer" /> The asteroid 1810 Epimetheus is named after his brother. The official {{MoMP|1809|naming citation}} was published by the Minor Planet Center on 20 February 1976 ({{small|M.P.C. 3934}}).<ref name="DoMP-Circular-dates" />
== Physical characteristics ==
According to the surveys carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Prometheus measures 14.2 kilometers in diameter, and its surface has an albedo of 0.126.<ref name="Masiero-2014" /> As of 2017, its spectral type, rotation period and shape remain unknown.
== References == {{reflist|30em|refs=
<ref name="jpldata">{{cite web |type = 2017-03-29 last obs. |title = JPL Small-Body Database Browser: 1809 Prometheus (2522 P-L) |url = https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2001809 |archive-url = https://web.archive.org/web/20161220143829/http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2001809 |url-status = dead |archive-date = 20 December 2016 |publisher = Jet Propulsion Laboratory |accessdate = 3 June 2017}}</ref>
<ref name="springer">{{cite book |title = Dictionary of Minor Planet Names – (1809) Prometheus |last = Schmadel | first = Lutz D. |publisher = Springer Berlin Heidelberg |page = 145 |date = 2007 |isbn = 978-3-540-00238-3 |doi = 10.1007/978-3-540-29925-7_1810 |chapter = (1809) Prometheus }}</ref>
<ref name="MPC-Prometheus">{{cite web |title = 1809 Prometheus (2522 P-L) |work = Minor Planet Center |url = https://www.minorplanetcenter.net/db_search/show_object?object_id=1809 |accessdate = 15 December 2016}}</ref>
<ref name="MPC-discoverers">{{cite web |title = Minor Planet Discoverers |work = Minor Planet Center |url = https://www.minorplanetcenter.net/iau/lists/MPDiscsNum.html |date = 24 April 2016 |accessdate = 15 December 2016}}</ref>
<ref name="DoMP-Circular-dates">{{cite book |title = Dictionary of Minor Planet Names – Addendum to Fifth Edition (2006–2008) |chapter = Appendix – Publication Dates of the MPCs |last = Schmadel |first=Lutz D. |publisher = Springer Berlin Heidelberg |page = 221 |isbn = 978-3-642-01964-7 |doi = 10.1007/978-3-642-01965-4}}</ref>
<ref name="Masiero-2014">{{cite journal |display-authors = 6 |first1 = Joseph R. |last1 = Masiero |first2 = T. |last2 = Grav |first3 = A. K. |last3 = Mainzer |first4 = C. R. |last4 = Nugent |first5 = J. M. |last5 = Bauer |first6 = R. |last6 = Stevenson |first7 = S. |last7 = Sonnett |date = August 2014 |title = Main-belt Asteroids with WISE/NEOWISE: Near-infrared Albedos |url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2014ApJ...791..121M |journal = The Astrophysical Journal |volume = 791 |issue = 2 |page = 11 |bibcode = 2014ApJ...791..121M |doi = 10.1088/0004-637X/791/2/121 |arxiv = 1406.6645 |access-date= 15 December 2016}}</ref>
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== External links == * [http://www.minorplanet.info/PHP/lcdbsummaryquery.php Asteroid Lightcurve Database (LCDB)], query form ([http://www.minorplanet.info/lightcurvedatabase.html info] {{Webarchive|url=https://web.archive.org/web/20171216050541/http://www.minorplanet.info/lightcurvedatabase.html |date=16 December 2017 }}) * [https://books.google.com/books?id=aeAg1X7afOoC&pg Dictionary of Minor Planet Names], Google books * [http://obswww.unige.ch/~behrend/page_cou.html Asteroids and comets rotation curves, CdR] – Observatoire de Genève, Raoul Behrend * [https://www.minorplanetcenter.net/iau/lists/NumberedMPs000001.html Discovery Circumstances: Numbered Minor Planets (1)-(5000)] – Minor Planet Center * {{AstDys|1809}} * {{JPL small body}}
{{Minor planets navigator |1808 Bellerophon |number=1809 |1810 Epimetheus}} {{Small Solar System bodies}} {{Authority control}}
{{DEFAULTSORT:Prometheus}} 001809 2522 Category:Discoveries by Tom Gehrels Category:Discoveries by Cornelis Johannes van Houten Category:Discoveries by Ingrid van Houten-Groeneveld Category:Named minor planets 19600924