View source for Astronomy:9023 Mnesthus

{{Infobox planet
 | minorplanet     = yes
 | name            = 9023 Mnesthus
 | background      = #C2FFFF
 | image           = 
 | image_size      = 
 | caption         = 
 | discovery_ref   = &thinsp;<ref name="MPC-object" />
 | discoverer      = C. Shoemaker<br />E. Shoemaker
 | discovery_site  = [[Organization:Palomar Observatory|Palomar Obs.]]
 | discovered      = 10 September 1988
 | mpc_name        = (9023) Mnesthus
 | alt_names       = {{mp|1988 RG|1}}
 | pronounced      = {{IPAc-en|ˈ|n|ɛ|s|θ|ə|s|,_|-|θ<!--/θj/ is now just /θ/-->|uː|s}}<ref>'Mnestheus' in Noah Webster (1884) ''A Practical Dictionary of the English Language''</ref>
 | adjective       = Mnesthian
 | named_after     = Mnestheus&thinsp;<ref name="MPC-object" /><br />{{small|(Greco-Roman mythology)}}
 | mp_category     = [[Astronomy:Jupiter trojan|Jupiter trojan]]&thinsp;<ref name="MPC-object" /><ref name="jpldata" /><br />{{nowrap|Trojan&thinsp;<ref name="MPC-Jupiter-Trojans" />{{·}}[[Astronomy:Background asteroid|background]]&thinsp;<ref name="AstDys-object" />}}
 | orbit_ref       = &thinsp;<ref name="jpldata" />
 | epoch           = 23 March 2018 ([[Astronomy:Julian day|JD]] 2458200.5)
 | uncertainty     = 0
 | observation_arc = 67.76 [[Astronomy:Julian year|yr]] (24,750 d)
 | aphelion        = 5.5611 [[Astronomy:Astronomical unit|AU]]
 | perihelion      = 4.8924 AU
 | semimajor       = 5.2268 AU
 | eccentricity    = 0.0640
 | period          = 11.95 yr (4,365 d)
 | mean_anomaly    = 192.08[[Degree (angle)|°]]
 | mean_motion     = {{Deg2DMS|0.0825|sup=ms}} / day
 | inclination     = 23.917°
 | asc_node        = 159.89°
 | arg_peri        = 158.39°
 | jupiter_moid    = 0.0701 AU
 | tisserand       = 2.8240
 | mean_diameter   = {{val|49.15|0.59|ul=km}}<ref name="Grav-2012" /><br />{{val|60.80|4.15|u=km}}<ref name="AKARI" />
 | rotation        = {{val|30.66|0.01|ul=h}}<ref name="French-2012" />{{efn|name=lightcurve-plots-CS3}}
 | albedo          = {{val|0.033|0.005}}<ref name="AKARI" /><br />{{val|0.073|0.014}}<ref name="Grav-2012" />
 | spectral_type   = [[Astronomy:C-type asteroid|C]] {{small|(assumed)}}<ref name="lcdb" />
 | abs_magnitude   = 10.0<ref name="Grav-2012" /><br />10.1<ref name="MPC-object" /><ref name="jpldata" /><br />10.2<ref name="lcdb" /><br />10.40<ref name="AKARI" />
}}

'''9023 Mnesthus''' {{IPAc-en|ˈ|n|ɛ|s|θ|ə|s}} is a large [[Astronomy:Jupiter trojan|Jupiter trojan]] from the Trojan camp, approximately {{convert|50|km|mi|abbr=off|sigfig=2|sp=us}} in diameter. It was discovered on 10 September 1988, by American astronomer couple Carolyn and Eugene Shoemaker at the [[Organization:Palomar Observatory|Palomar Observatory]] in California.<ref name="MPC-object" /> The dark Jovian [[Astronomy:Asteroid|asteroid]] belongs to the 100 largest Jupiter trojans and has a longer-than-average [[Rotation period|rotation period]] of 30.7 hours.<ref name="lcdb" /> It was named after the Trojan Mnestheus, a companion of Aeneas in Classical mythology.<ref name="MPC-object" />

== Orbit and classification ==

''Mnesthus'' is a dark Jovian [[Astronomy:Asteroid|asteroid]] in a 1:1 orbital resonance with Jupiter. It is located in the trailering Trojan camp at the Gas Giant's {{L5}} [[Astronomy:Lagrangian point|Lagrangian point]], 60[[Degree (angle)|°]] behind its orbit {{crossreference|(see Trojans in astronomy)}}.<ref name="MPC-Jupiter-Trojans" /> It is also a non-[[Astronomy:Asteroid family|family]] asteroid of the [[Astronomy:Background asteroid|Jovian background population]].<ref name="AstDys-object" />

It orbits the Sun at a distance of 4.9–5.6&nbsp;[[Astronomy:Astronomical unit|AU]] once every 11 years and 11 months (4,365 days; semi-major axis of 5.23&nbsp;AU). Its orbit has an [[Astronomy:Orbital eccentricity|eccentricity]] of 0.06 and an [[Astronomy:Orbital inclination|inclination]] of 24[[Degree (angle)|°]] with respect to the [[Astronomy:Ecliptic|ecliptic]].<ref name="jpldata" /> The body's [[Astronomy:Observation arc|observation arc]] begins with a [[Astronomy:Precovery|precovery]] at Palomar in July 1950, more than 38 years prior to its official discovery observation.<ref name="MPC-object" />

== Naming ==

This [[Astronomy:Minor planet|minor planet]] was named from Greco-Roman mythology after the Trojan Mnestheus, a companion and officer of Aeneas in Classical mythology. He is one of the wandering Aeneads who traveled to Italy after the downfall of Troy. At the funeral games for Aeneas' father, Anchises, he competes in both the sailing and the archery contests, winning second place in sailing.<ref name="MPC-object" /> The official naming citation was published by the [[Organization:Minor Planet Center|Minor Planet Center]] on 13 October 2000 ({{small|M.P.C. 41384}}).<ref name="MPC-Circulars-Archive" />

== Physical characteristics ==

''Mnesthus'' is an assumed [[Astronomy:C-type asteroid|C-type asteroid]].<ref name="lcdb" /> Jovian asteroids are typically [[Astronomy:D-type asteroid|D-types]], with the remainder being mostly carbonaceous C- and primitive [[Astronomy:P-type asteroid|P-type asteroid]]s.

=== Rotation period ===

In August 2011, a rotational [[Astronomy:Lightcurve|lightcurve]] of ''Mnesthus'' was obtained from [[Astronomy:Photometry|photometric]] observations by Daniel Coley and Robert Stephens at the Center for Solar System Studies and GMARS {{Obscode|G79}}, respectively. Lightcurve analysis gave a longer-than average [[Rotation period|rotation period]] of {{val|30.66|0.01}} hours with a brightness amplitude of 0.23 [[Astronomy:Magnitude|magnitude]] ({{small|U=2+}}).<ref name="French-2012" /><ref name="lcdb" />{{efn|name=lightcurve-plots-CS3}}

=== Diameter and albedo ===

According to the surveys carried out by the [[Astronomy:NEOWISE|NEOWISE]] mission of NASA's [[Astronomy:Wide-field Infrared Survey Explorer|Wide-field Infrared Survey Explorer]] and the Japanese [[Astronomy:Akari (satellite)|Akari satellite]], ''Mnesthus'' measures 49.15 and 60.80 kilometers in diameter and its surface has an [[Astronomy:Astronomical albedo|albedo]] of 0.073 and 0.033, respectively.<ref name="Grav-2012" /><ref name="AKARI" /> The ''Collaborative Asteroid Lightcurve Link'' assumes a standard albedo for a carbonaceous asteroid of 0.057 and calculates a diameter of 50.77 kilometers based on an [[Astronomy:Absolute magnitude|absolute magnitude]] of 10.2.<ref name="lcdb" />

{{Largest Jupiter trojans}}

== Notes ==
{{notelist|refs=

{{efn|name=lightcurve-plots-CS3|1=Lightcurve plots of (9023) Mnesthus from [http://www.planetarysciences.org/plots/DC/9023_MNESTHUS_2011-07-23.BMP Aug 2011] by Daniel Coley at the Center for Solar System Studies {{Obscode|U80}}. Quality code is 2- (lightcurve rating at CS3). Summary figures at the [http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=9023%7CMnesthus LCDB] and [http://www.planetarysciences.org/PHP/CS3_Lightcurves.php CS3].}}

}} <!-- end of notelist -->

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

<ref name="jpldata">{{cite web
  |type       = 2018-04-23 last obs.
  |title      = JPL Small-Body Database Browser: 9023 Mnesthus (1988 RG1)
  |url        = https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2009023
  |publisher  = [[Organization:Jet Propulsion Laboratory|Jet Propulsion Laboratory]]
  |access-date = 22 June 2018}}</ref>

<ref name="MPC-object">{{cite web
  |title      = 9023 Mnesthus (1988 RG1)
  |work       = Minor Planet Center
  |url        = https://www.minorplanetcenter.net/db_search/show_object?object_id=9023
  |access-date = 22 June 2018}}</ref>

<ref name="MPC-Jupiter-Trojans">{{cite web
  |title      = List of Jupiter Trojans
  |work       = Minor Planet Center
  |first3     = V. |last3 = Carruba
  |date       = 1 June 2018
  |url        = https://www.minorplanetcenter.net/iau/lists/JupiterTrojans.html
  |access-date = 22 June 2018}}</ref>

<ref name="MPC-Circulars-Archive">{{cite web
  |title      = MPC/MPO/MPS Archive
  |work       = Minor Planet Center
  |url        = https://www.minorplanetcenter.net/iau/ECS/MPCArchive/MPCArchive_TBL.html
  |access-date = 22 June 2018}}</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
  |url        = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2012ApJ...759...49G
  |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
 |access-date= 22 June 2018}} ([http://vizier.cfa.harvard.edu/viz-bin/VizieR-6?-source=J/ApJ/759/49/table1&MPC=09023 online catalog])</ref>

<ref name="AstDys-object">{{cite web
  |title      = Asteroid (9023) Mnesthus – Proper Elements
  |publisher  = AstDyS-2, Asteroids – Dynamic Site
  |url        = https://newton.spacedys.com/astdys/index.php?n=9023&pc=1.1.6
  |access-date= 22 June 2018}}</ref>

<ref name="lcdb">{{cite web
  |title      = LCDB Data for (9023) Mnesthus
  |publisher  = Asteroid Lightcurve Database (LCDB)
  |url        = http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=9023%7CMnesthus
  |access-date = 22 June 2018}}</ref>

<ref name="AKARI">{{cite journal
  |display-authors = 6
  |first1     = Fumihiko |last1 = Usui
  |first2     = Daisuke |last2 = Kuroda
  |first3     = Thomas G. |last3 = Müller
  |first4     = Sunao |last4 = Hasegawa
  |first5     = Masateru |last5 = Ishiguro
  |first6     = Takafumi |last6 = Ootsubo
  |first7     = Daisuke |last7 = Ishihara
  |first8     = Hirokazu |last8 = Kataza
  |first9     = Satoshi |last9 = Takita
  |first10    = Shinki |last10 = Oyabu
  |first11    = Munetaka |last11 = Ueno
  |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= 
  }} ([http://vizier.cfa.harvard.edu/viz-bin/VizieR-5?-source=J/PASJ/63/1117/acua_v1&Num=9023 online], [https://core.ac.uk/download/pdf/43545172.pdf AcuA catalog p. 153])</ref>

<ref name="French-2012">{{Cite journal
  |first1     = Linda M. |last1 = French
  |first2     = Robert D. |last2 = Stephens
  |first3     = Daniel R. |last3 = Coley
  |first4     = Ralph |last4 = Megna
  |first5     = Lawrence H. |last5 = Wasserman
  |date       = July 2012
  |title      = Photometry of 17 Jovian Trojan Asteroids
  |url        = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2012MPBu...39..183F
  |journal    = The Minor Planet Bulletin
  |volume     = 39
  |issue      = 3
  |pages      = 183–187
  |issn       = 1052-8091
  |bibcode    = 2012MPBu...39..183F
  |access-date= 22 June 2018}}</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/NumberedMPs005001.html Discovery Circumstances: Numbered Minor Planets (5001)-(10000)] – Minor Planet Center
* [https://sbntools.psi.edu/ferret/SimpleSearch/results.action?targetName=9023+Mnesthus Asteroid 9023 Mnesthus] at the Small Bodies Data Ferret
* {{AstDys|9023}}
* {{JPL small body}}

{{Small Solar System bodies}}

{{DEFAULTSORT:Mnesthus}}
[[Category:Named minor planets]]

{{Sourceattribution|9023 Mnesthus}}