View source for Astronomy:1437 Diomedes

{{Short description|Trojan asteroid}}
{{Infobox planet
 | minorplanet     = yes
 | name            = 1437 Diomedes
 | background      = #C2FFFF
 | image           = 001437-asteroid shape model (1437) Diomedes.png
 | image_scale      =
 | caption         = Modelled shape of ''Diomedes'' from its [[Astronomy:Light curve|light curve]]
 | discovery_ref   = <ref name="MPC-object" />
 | discoverer      = K. Reinmuth
 | discovery_site  = [[Organization:Heidelberg-Königstuhl State Observatory|Heidelberg Obs.]]
 | discovered      = 3 August 1937
 | mpc_name        = (1437) Diomedes
 | alt_names       = 1937 PB{{·}}1931 DN<br />1936 PQ{{·}}1971 RD
 | adjective       = Diomedian
 | pronounced      = {{IPAc-en|ˌ|d|aɪ|ə|ˈ|m|iː|d|iː|z}}<ref>{{MW|Diomedes}}</ref>
 | named_after     = Diomedes<ref name="springer" /><br />{{small|(Greek mythology)}}
 | mp_category     = [[Astronomy:Jupiter trojan|Jupiter trojan]]<ref name="MPC-object" /><ref name="jpldata" /><ref name="lcdb" /><br />{{nowrap|Greek<ref name="MPC-Jupiter-Trojans" /><ref name="AstDys-object" />{{·}}[[Astronomy:Background asteroid|background]]<ref name="AstDys-object" />}}
 | orbit_ref       = <ref name="jpldata" />
 | epoch           = 23 March 2018 ([[Astronomy:Julian day|JD]] 2458200.5)
 | uncertainty     = 0
 | observation_arc = 80.80 [[Astronomy:Julian year|yr]] (29,514 d)
 | aphelion        = 5.4248 [[Astronomy:Astronomical unit|AU]]
 | perihelion      = 4.9720 AU
 | semimajor       = 5.1984 AU
 | eccentricity    = 0.0435
 | period          = 11.85 yr (4,329 d)
 | mean_anomaly    = 234.43[[Degree (angle)|°]]
 | mean_motion     = {{Deg2DMS|0.0832|sup=ms}} / day
 | inclination     = 20.485°
 | asc_node        = 315.80°
 | arg_peri        = 130.93°
 | jupiter_moid    = 0.275 AU
 | tisserand       = 2.8720
 | dimensions      = {{val|284|×|126|×|65|ul=km}}<ref name="Ferret" /><ref name="Sato-2000" />
 | mean_diameter   = {{val|117.79|1.18|u=km}}<ref name="Grav-2012" /><br />{{val|132.5|u=km}}<ref name="Sato-2000" /><br />{{val|164.31|4.1|u=km}}<ref name="SIMPS" /><br />{{val|172.60|3.42|u=km}}<ref name="AKARI" /><br />{{val|173.0|u=km}}<ref name="Ferret" />
 | rotation        = {{val|16|ul=h}}<ref name="Binzel-1992a" /><br />{{val|18|u=h}}<ref name="Taylor-1971a" /><br />{{val|21|u=h}}<ref name="Dunlap-1969" /><br />{{val|24.46|u=h}}<ref name="Sato-2000" /><br />{{val|24.49|0.01|u=h}}<ref name="Mottola-2011" /><ref name="Stephens-2009b" />
 | albedo          = {{val|0.028|0.001}}<ref name="AKARI" /><br />{{val|0.0313|0.002}}<ref name="SIMPS" /><br />{{val|0.061|0.011}}<ref name="Grav-2012" />
 | spectral_type   = Tholen {{=}} [[Astronomy:D-type asteroid|D]][[Astronomy:P-type asteroid|P]]<ref name="jpldata" /><ref name="lcdb" /><ref name="Ferret" /><br />U–B {{=}} {{val|0.250|040}}<ref name="Ferret" /><br />B–V {{=}} {{val|0.700|014}}<ref name="Ferret" /><br />V–I {{=}} {{val|0.810|0.025}}<ref name="lcdb" />
 | abs_magnitude   = {{val|8.18|0.28}}<ref name="Veres-2015" /><br />8.30<ref name="MPC-object" /><ref name="jpldata" /><ref name="lcdb" /><ref name="Grav-2012" /><ref name="SIMPS" /><ref name="AKARI" />
}}

'''1437 Diomedes''' {{IPAc-en|ˌ|d|aɪ|ə|ˈ|m|iː|d|iː|z}} is a large [[Astronomy:Jupiter trojan|Jupiter trojan]] from the Greek camp, approximately {{convert|150|km|mi|abbr=off|sigfig=1|sp=us}} in diameter. It was discovered on 3 August 1937, by astronomer Karl Reinmuth at the [[Organization:Heidelberg-Königstuhl State Observatory|Heidelberg-Königstuhl State Observatory]] in southwest Germany.<ref name="MPC-object" /> The dark [[Astronomy:D-type asteroid|D]]/[[Astronomy:P-type asteroid|P-type asteroid]] belongs to the largest Jupiter trojans and has a notably elongated shape and a longer than average [[Rotation period|rotation period]] of 24.49 hours.<ref name="lcdb" /> ''Diomedes'' was the first Jupiter trojan successfully observed during an [[Astronomy:Asteroid occultation|occultation event]] of star.<ref name="Sato-2000" /> It was named after the hero Diomedes from Greek mythology.<ref name="springer" />

== Orbit and classification ==

''Diomedes'' is a dark Jovian [[Astronomy:Asteroid|asteroid]] orbiting in the leading Greek camp at Jupiter's {{L4}} [[Astronomy:Lagrangian point|Lagrangian point]], 60[[Degree (angle)|°]] ahead of the Gas Giant's orbit in a 1:1 resonance {{crossreference|(see Trojans in astronomy)}}. It is also a non-[[Astronomy:Asteroid family|family]] asteroid in the [[Astronomy:Background asteroid|Jovian background population]].<ref name="AstDys-object" /> Jupiter trojans are thought to have been captured into their orbits during or shortly after the early stages of the formation of the Solar System. More than 4,500 Jupiter trojans in the Greek camp have already been discovered.<ref name="MPC-Jupiter-Trojans" />

It orbits the Sun at a distance of 5.0–5.4&nbsp;[[Astronomy:Astronomical unit|AU]] once every 11 years and 10 months (4,329 days; semi-major axis of 5.2&nbsp;AU). Its orbit has an [[Astronomy:Orbital eccentricity|eccentricity]] of 0.04 and an [[Astronomy:Orbital inclination|inclination]] of 20[[Degree (angle)|°]] with respect to the [[Astronomy:Ecliptic|ecliptic]].<ref name="jpldata" /> The asteroid was first observed as ''{{mp|1931 DN}}'' at [[Astronomy:Lowell Observatory|Lowell Observatory]] in February 1931. The body's [[Astronomy:Observation arc|observation arc]] begins at Heidelberg with its official discovery observation in August 1937.<ref name="MPC-object" />

== Physical characteristics ==
<div style="float:left; font-size: 0.9em; margin-right: 20px; margin-top: 0;">
{{JPL SBDB Jupiter Trojans}}
</div>

In the Tholen classification, ''Diomedes'' has an ambiguous [[Astronomy:Asteroid spectral type|spectral type]], closest to the dark [[Astronomy:D-type asteroid|D-type asteroid]]s and somewhat similar to the primitive [[Astronomy:P-type asteroid|P-type asteroid]]s.<ref name="jpldata" /> Its V–I color index of 0.810 is also lower than that measured for most D-type Jupiter trojans (0.95).<ref name="lcdb" />

=== Rotation period ===

Several rotational [[Astronomy:Lightcurve|lightcurve]]s of ''Diomedes'' have been obtained from [[Astronomy:Photometry|photometric]] observations since the 1960s.<ref name="Sato-2000" /><ref name="Binzel-1992a" /><ref name="Taylor-1971a" /><ref name="Dunlap-1969" /><ref name="Mottola-2011" /> The so-far best-rated photometric observations by Robert Stephens at the Goat Mountain Astronomical Research Station {{Obscode|G79}} and Santana Observatory {{Obscode|646}} in November 2008, gave a longer-than average [[Rotation period|rotation period]] of {{val|24.49|0.01}} hours with a brightness variation of 0.34 [[Astronomy:Magnitude|magnitude]] ({{small|U=3-}}).<ref name="Stephens-2009b" />

=== Diameter and albedo ===

In the 1970s, radiometric observations were published in the Tucson Revised Index of Asteroid Data (TRIAD) compilation gave a diameter of 173.0 kilometers with a radiometric [[Astronomy:Astronomical albedo|albedo]] 0.021.<ref name="Ferret" />

According to the space-based surveys carried out by the Infrared Astronomical Satellite [[Astronomy:IRAS|IRAS]], the Japanese [[Astronomy:Akari (satellite)|Akari satellite]] and the [[Astronomy:NEOWISE|NEOWISE]] mission of NASA's [[Astronomy:Wide-field Infrared Survey Explorer|Wide-field Infrared Survey Explorer]], ''Diomedes'' measures between 117.786 and 172.60 kilometers in diameter and its surface has an albedo between 0.028 and 0.061.<ref name="Grav-2012" /><ref name="SIMPS" /><ref name="AKARI" /> The ''Collaborative Asteroid Lightcurve Link'' adopts the results obtained by IRAS, that is, an albedo of 0.0313 and a diameter of 164.31 kilometers based on an [[Astronomy:Absolute magnitude|absolute magnitude]] of 8.30.<ref name="lcdb" /> The ''Collaborative Asteroid Lightcurve Link'' adopts the results obtained by IRAS, that is, an albedo of 0.0313 and a diameter of 164.31 kilometers based on an [[Astronomy:Absolute magnitude|absolute magnitude]] of 8.30.<ref name="lcdb" />

''Diomedes'' is the third largest Jupiter trojan according to IRAS and Akari, and the 9th largest based on NEOWISE data:  
{{Largest Jupiter trojans}}

=== Occultation and shape ===

''Diomedes'' was the first Jupiter trojan that was successfully observed during an [[Astronomy:Asteroid occultation|asteroid occultation]], when it occulted the star ''HIP 014402A'' over Japan on 7 November 1997. The silhouette was elongated with a major and minor occultation axis of {{val|284|×|126}} kilometers (poor fit).<ref name="Ferret" /><ref name="Sato-2000" /> The ellipsoid dimensions of {{val|284|×|126|×|65}} kilometers – corresponding to a [[Geometric mean|mean]]-diameter of 132.5 kilometers, equivalent to the volume of a sphere – were estimated using follow-up photometry at Ondřejov Observatory and Mitaka Observatory {{Obscode|388}} that determined the body's rotational phase at the exact time of the occultation event.<ref name="Sato-2000" />

== Naming ==

This [[Astronomy:Minor planet|minor planet]] was named from [[Religion:Greek mythology|Greek mythology]] after the hero Diomedes, King of Argos and known for his participation in the Trojan War, regarded as the best warriors of the Achaeans, just behind Achilles and alongside Ajax. The official naming citation was mentioned in ''The Names of the Minor Planets'' by Paul Herget in 1955 ({{small|H 129}}).<ref name="springer" />

== References ==
{{reflist|30em|refs=

<ref name="jpldata">{{cite web
  |type       = 2017-09-27 last obs.
  |title      = JPL Small-Body Database Browser: 1437 Diomedes (1937 PB)
  |url        = https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2001437
  |archive-url = https://web.archive.org/web/20200711150459/https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2001437
  |url-status = dead
  |archive-date = 11 July 2020
  |publisher  = [[Organization:Jet Propulsion Laboratory|Jet Propulsion Laboratory]]
  |access-date = 26 October 2017}}</ref>

<ref name="springer">{{cite book
  |last       = Schmadel | first = Lutz D.
  |title = Dictionary of Minor Planet Names |publisher  = Springer Berlin Heidelberg
  |page       = 115
  |date       = 2007
  |isbn       = 978-3-540-00238-3
  |doi       = 10.1007/978-3-540-29925-7_1438 |chapter       = (1437) Diomedes }}</ref>

<ref name="MPC-object">{{cite web
  |title      = 1437 Diomedes (1937 PB)
  |work       = Minor Planet Center
  |url        = https://www.minorplanetcenter.net/db_search/show_object?object_id=1437
  |access-date = 26 October 2017}}</ref>

<ref name="MPC-Jupiter-Trojans">{{cite web
  |title      = List of Jupiter Trojans
  |work       = Minor Planet Center
  |date       = 7 October 2017
  |url        = https://www.minorplanetcenter.net/iau/lists/JupiterTrojans.html
  |access-date = 26 October 2017}}</ref>

<ref name="Grav-2012">{{cite journal
  |first1     = T. |last1 = Grav
  |first2     = A. K. |last2 = Mainzer
  |first3     = J. M. |last3 = Bauer
  |first4     = J. R. |last4 = Masiero
  |first5     = C. R. |last5 = Nugent
  |date       = November 2012
  |title      = WISE/NEOWISE Observations of the Jovian Trojan Population: Taxonomy
  |journal    = The Astrophysical Journal
  |volume     = 759
  |issue      = 1
  |page       = 10
  |bibcode    = 2012ApJ...759...49G
  |doi        = 10.1088/0004-637X/759/1/49
  |arxiv      = 1209.1549
  |s2cid = 119101711
 }} ([http://vizier.cfa.harvard.edu/viz-bin/VizieR-6?-source=J/ApJ/759/49/table1&MPC=01437 online catalog])</ref>

<ref name="AstDys-object">{{cite web
  |title      = Asteroid (1437) Diomedes – Proper elements
  |publisher  = AstDyS-2, Asteroids – Dynamic Site
  |url        = https://newton.spacedys.com/astdys/index.php?n=1437&pc=1.1.6
  |access-date = 13 June 2018}}</ref>

<ref name="Ferret">{{cite web
  |title      = Asteroid 1437 Diomedes
  |work       = Small Bodies Data Ferret
  |url        = https://sbntools.psi.edu/ferret/SimpleSearch/results.action?targetName=1437+Diomedes
  |access-date = 13 June 2018}}</ref>

<ref name="lcdb">{{cite web
  |title      = LCDB Data for (1437) Diomedes
  |publisher  = Asteroid Lightcurve Database (LCDB)
  |url        = http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=1437%7CDiomedes
  |access-date = 26 October 2017}}</ref>

<ref name="AKARI">{{cite journal
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  |first8     = Hirokazu |last8 = Kataza
  |first9     = Satoshi |last9 = Takita
  |first10    = Shinki |last10 = Oyabu
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  |first12    = Hideo |last12 = Matsuhara
  |first13    = Takashi |last13 = Onaka
  |date       = October 2011
  |title      = Asteroid Catalog Using Akari: AKARI/IRC Mid-Infrared Asteroid Survey
  |journal    = Publications of the Astronomical Society of Japan
  |volume     = 63
  |issue      = 5
  |pages      = 1117–1138
  |bibcode    = 2011PASJ...63.1117U
  |doi        = 10.1093/pasj/63.5.1117
  |doi-access= free
  }} ([http://vizier.cfa.harvard.edu/viz-bin/VizieR-5?-source=J/PASJ/63/1117/acua_v1&Num=1437 online], [https://core.ac.uk/download/pdf/43545172.pdf AcuA catalog p. 153])</ref>

<ref name="SIMPS">{{cite journal
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  |date       = October 2004
  |title      = IRAS Minor Planet Survey V6.0
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  |journal    = NASA Planetary Data System – IRAS-A-FPA-3-RDR-IMPS-V6.0
  |pages = IRAS-A-FPA-3-RDR-IMPS-V6.0
  |bibcode    = 2004PDSS...12.....T
  |access-date = 15 June 2018}}</ref>

<ref name="Dunlap-1969">{{Cite journal
  |first1     = J. L. |last1 = Dunlap
  |first2     = T. |last2 = Gehrels
  |date       = August 1969
  |title      = Minor Planets. III. Lightcurves of a Trojan Asteroid
  |url        = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=1969AJ.....74..796D
  |journal    = Astronomical Journal
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  |doi        = 10.1086/110860
  |access-date= 26 October 2017}}</ref>

<ref name="Taylor-1971a">{{Cite journal
  |author     = Taylor, Ronald C.
  |date       = December 1970
  |title      = Photometric Observations and Reductions of Lightcurves of Asteroids
  |url        = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=1971NASSP.267..117T
  |journal    = Physical Studies of Minor Planets
  |volume       = 267
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  |access-date= 26 October 2017}}</ref>

<ref name="Binzel-1992a">{{Cite journal
  |first1     = Richard P. |last1 = Binzel
  |first2     = Linda M. |last2 = Sauter
  |date       = February 1992
  |title      = Trojan, Hilda, and Cybele asteroids – New lightcurve observations and analysis
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  |access-date= 26 October 2017}}</ref>

<ref name="Sato-2000">{{Cite journal
  |first1     = Isao |last1 = Sato
  |first2     = Lenka |last2 = Sarounová
  |first3     = Hideo |last3 = Fukushima
  |date       = May 2000
  |title      = Size and Shape of Trojan Asteroid Diomedes from Its Occultation and Photometry
  |url        = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2000Icar..145...25S
  |journal    = Icarus
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  |doi        = 10.1006/icar.1999.6316
  |access-date= 26 October 2017}}</ref>

<ref name="Stephens-2009b">{{Cite journal
  |author     = Stephens, Robert D.
  |date       = April 2009
  |title      = Asteroids Observed from GMARS and Santana Observatories
  |url        = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2009MPBu...36...59S
  |journal    = The Minor Planet Bulletin
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<ref name="Mottola-2011">{{cite journal
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  |first10    = Marco |last10 = Delbò
  |first11    = Claes-Ingvar |last11 = Lagerkvist
  |date       = May 2011
  |title      = Rotational Properties of Jupiter Trojans. I. Light Curves of 80 Objects
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  |bibcode    = 2011AJ....141..170M
  |doi        = 10.1088/0004-6256/141/5/170|doi-access= free
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<ref name="Veres-2015">{{cite journal
  |display-authors = 6
  |first1     = Peter |last1 = Veres
  |first2     = Robert |last2 = Jedicke
  |first3     = Alan |last3 = Fitzsimmons
  |first4     = Larry |last4 = Denneau
  |first5     = Mikael |last5 = Granvik
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  |first7     = Serge |last7 = Chastel
  |first8     = Richard J. |last8 = Wainscoat
  |first9     = William S. |last9 = Burgett
  |first10    = Kenneth C. |last10 = Chambers
  |first11    = Heather |last11 = Flewelling
  |first12    = Nick |last12 = Kaiser
  |first13    = Eugen A. |last13 = Magnier
  |first14    = Jeff S. |last14 = Morgan
  |first15    = Paul A. |last15 = Price
  |first16    = John L. |last16 = Tonry
  |first17    = Christopher |last17 = Waters
  |date       = November 2015
  |title      = Absolute magnitudes and slope parameters for 250,000 asteroids observed by Pan-STARRS PS1 – Preliminary results
  |journal    = Icarus
  |volume     = 261
  |pages      = 34–47
  |bibcode    = 2015Icar..261...34V
  |doi        = 10.1016/j.icarus.2015.08.007
  |arxiv      = 1506.00762|s2cid = 53493339 }}</ref>

}} <!-- end of reflist -->

== 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
* [https://www.minorplanetcenter.net/iau/lists/NumberedMPs000001.html Discovery Circumstances: Numbered Minor Planets (1)-(5000)] – Minor Planet Center
* {{AstDys|1437}}
* {{JPL small body}}

{{Small Solar System bodies}}

{{DEFAULTSORT:Diomedes}}
[[Category:Named minor planets]]
[[Category:DP-type asteroids (Tholen)|001437]]

{{Sourceattribution|1437 Diomedes}}