5648 Axius

{{Short description|Trojan asteroid}} {{Use dmy dates|date=June 2018}} {{Infobox planet | minorplanet = yes | name = 5648 Axius | background = #C2FFFF | image = | image_size = | caption = | discovery_ref = <ref name="MPC-object" /> | discoverer = K. Endate K. Watanabe | discovery_site = Kitami Obs. | discovered = 11 November 1990 | mpc_name = (5648) Axius | alt_names = {{mp|1990 VU|1}} | adjective = Axian | pronounced = | named_after = Axius {{small|(Greek mythology)}}<ref name="WGSBN-Bulletin-Archive" /> | mp_category = Jupiter trojan<ref name="MPC-object" /><ref name="jpldata" /> {{nowrap|Trojan<ref name="MPC-Jupiter-Trojans" />{{·}}background<ref name="AstDys-object" />}} | orbit_ref = <ref name="jpldata" /> | epoch = 23 March 2018 (JD 2458200.5) | uncertainty = 0 | observation_arc = 67.94 yr (24,816 d) | aphelion = 6.0024 AU | perihelion = 4.3016 AU | semimajor = 5.1520 AU | eccentricity = 0.1651 | period = 11.69 yr (4,271 d) | mean_anomaly = 178.01° | mean_motion = {{Deg2DMS|0.0843|sup=ms}} / day | inclination = 22.693° | asc_node = 71.048° | arg_peri = 268.85° | jupiter_moid = 0.0521 AU | tisserand = 2.8210 | mean_diameter = {{val|59.30|1.35|ul=km}}<ref name="Grav-2012" /> {{val|63.91|u=km}} {{small|(calculated)}}<ref name="lcdb" /> | rotation = {{val|37.56|0.05|ul=h}}<ref name="Mottola-2011" /> | albedo = {{val|0.057}} {{small|(assumed)}}<ref name="lcdb" /> {{val|0.073|0.015}}<ref name="Grav-2012" /> | spectral_type = D {{small|(S3OS2)}}<ref name="Lazzaro-2004" /> B–V {{=}} {{val|0.730|0.060}}<ref name="Chatelain-2016" /> V–R {{=}} {{val|0.480|0.040}}<ref name="Chatelain-2016" /> V–I {{=}} {{val|0.900|0.032}}<ref name="lcdb" /> | abs_magnitude = 9.6<ref name="Grav-2012" /> 9.7<ref name="MPC-object" /><ref name="jpldata" /><ref name="lcdb" /> }}

'''5648 Axius''', ''provisional designation'': {{mp|1990 VU|1}}, is a Jupiter trojan from the Trojan camp, approximately {{convert|60|km|mi|abbr=off|sigfig=2|sp=us}} in diameter. It was discovered on 11 November 1990, by Japanese amateur astronomers Kin Endate and Kazuro Watanabe at the Kitami Observatory on the northern island of Hokkaidō, Japan.<ref name="MPC-object" /> The dark D-type asteroid belongs to the 70 largest Jupiter trojans and has a long rotation period of 37.6 hours.<ref name="lcdb" /> It was named after Axius, a river god from Greek mythology.<ref name="WGSBN-Bulletin-Archive" />

== Orbit and classification ==

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

It orbits the Sun at a distance of 4.3–6.0 AU once every 11 years and 8 months (4,271 days; semi-major axis of 5.15 AU). Its orbit has an eccentricity of 0.17 and an inclination of 23° with respect to the ecliptic.<ref name="jpldata" /> The body's observation arc begins with a precovery taken at the Palomar Observatory in June 1950, more than 40 years prior to its official discovery observation.<ref name="MPC-object" />

== Numbering and naming ==

This minor planet was numbered on 1 September 1993 ({{small|M.P.C. 22480}}).<ref name="MPC-Circulars-Archive" /> On 14 May 2021, the object was named by the Working Group for Small Bodies Nomenclature (WGSBN), after Axius, a river god from Greek mythology, who is the son of Oceanus and Tethys, the father of Pelegon and grandfather of Asteropaios.<ref name="WGSBN-Bulletin-Archive" />

== Physical characteristics ==

In both the Tholen- and SMASS-like taxonomy of the Small Solar System Objects Spectroscopic Survey (S3OS2), ''Axius'' is a dark D-type asteroid, the dominant spectral type among the larger Jupiter trojans.<ref name="Lazzaro-2004" /><ref name="Ferret" /> It has a typical V–I color index of 0.90.<ref name="lcdb" />

=== Rotation period ===

In February 2005, Federico Manzini at the Sozzago Astronomical Station {{Obscode|A12}} in Italy obtained the first rotational lightcurve of ''Axius''. It gave a tentative rotation period of 16.04 hours with a brightness amplitude of 0.22 based on three nights of observation magnitude ({{small|U=2}}).<ref name="lcdb" /><ref name="geneva-obs" />

In June 2006, photometric observations over eight nights were made by Italian astronomer Stefano Mottola at the Calar Alto Observatory in Spain. Lightcurve analysis gave a rotation period of {{val|37.56|0.05}} hours with a brightness amplitude of 0.20 magnitude ({{small|U=3-}}), superseding Manzini's previous result.<ref name="Mottola-2011" /> A concurring period of 37.6083 hours with an amplitude of 0.19 magnitude was measured by astronomers at the Palomar Transient Factory in October 2013 ({{small|U=2}}).<ref name="Waszczak-2016" /> While not being a slow rotator, its period is significantly longer than that of most larger Jupiter trojans ''(see list below)''.

=== Diameter and albedo ===

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, ''Axius'' measures 59.30 kilometers in diameter and its surface has an albedo 0.073,<ref name="Grav-2012" /> while the ''Collaborative Asteroid Lightcurve Link'' assumes a standard albedo for a carbonaceous asteroid of 0.057 and calculates a diameter of 63.91 kilometers based on an absolute magnitude of 9.7.<ref name="lcdb" /> A diameter measurement for this asteroid has not been previously published by Akari and IRAS.{{efn|name=no-diameter-published}}

== Notes == {{notelist|refs=

{{efn|name=no-diameter-published|1=No diameter given in the Asteroid Catalog Using Akari: AKARI/IRC Mid-Infrared Asteroid Survey, see [https://core.ac.uk/download/pdf/43545172.pdf AcuA catalog p. 153] and in the IRAS Minor Planet Survey V6.0 (SIMPS), see [https://sbnarchive.psi.edu/pds3/iras/IRAS_A_FPA_3_RDR_IMPS_V6_0/data/diamalb.tab IRAS-A-FPA-3-RDR-IMPS-V6.0] at NASA's Planetary Data System.}}

}}

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

<ref name="jpldata">{{cite web |type = 2018-05-25 last obs. |title = JPL Small-Body Database Browser: 5648 (1990 VU1) |url = https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2005648 |publisher = Jet Propulsion Laboratory |access-date = 17 June 2018}}</ref>

<ref name="MPC-object">{{cite web |title = 5648 (1990 VU1) |work = Minor Planet Center |url = https://www.minorplanetcenter.net/db_search/show_object?object_id=5648 |access-date = 17 June 2018}}</ref>

<ref name="MPC-Jupiter-Trojans">{{cite web |title = List of Jupiter Trojans |work = Minor Planet Center |date = 30 May 2018 |url = https://www.minorplanetcenter.net/iau/lists/JupiterTrojans.html |access-date = 17 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 = 17 June 2018}}</ref>

<ref name="WGSBN-Bulletin-Archive">{{cite web |title = WGSBN Bulletin Archive |work = Working Group for Small Bodies Nomenclature |date = 14 May 2021 |url = https://www.wgsbn-iau.org/files/Bulletins/index.html |access-date = 16 May 2021}} ([https://www.wgsbn-iau.org/files/Bulletins/V001/WGSBNBull_V001_001.pdf Bulletin #1])</ref>

<ref name="geneva-obs">{{cite web |title = Asteroids and comets rotation curves – (5648) |last = Behrend |first = Raoul |publisher = Geneva Observatory |url = http://obswww.unige.ch/~behrend/page5cou.html#005648 |access-date = 29 June 2016}}</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=05648 online catalog])</ref>

<ref name="AstDys-object">{{cite web |title = Asteroid (5648) 1990 VU1 – Proper Elements |publisher = AstDyS-2, Asteroids – Dynamic Site |url = https://newton.spacedys.com/astdys/index.php?n=5648&pc=1.1.6 |access-date= 17 June 2018}}</ref>

<ref name="Ferret">{{cite web |title = Asteroid (5648) 1990 VU1 |work = Small Bodies Data Ferret |url = https://sbntools.psi.edu/ferret/SimpleSearch/results.action?targetName=5648 |access-date = 17 June 2018}}</ref>

<ref name="Lazzaro-2004">{{Cite journal |first1 = D. |last1 = Lazzaro |first2 = C. A. |last2 = Angeli |first3 = J. M. |last3 = Carvano |first4 = T. |last4 = Mothé-Diniz |first5 = R. |last5 = Duffard |first6 = M. |last6 = Florczak |date = November 2004 |title = S3OS2: the visible spectroscopic survey of 820 asteroids |url = http://sirrah.troja.mff.cuni.cz/yarko-site/tmp/eos/NEW/spectral_type_figure/s3os2.pdf |journal = Icarus |volume = 172 |issue = 1 |pages = 179–220 |bibcode = 2004Icar..172..179L |doi = 10.1016/j.icarus.2004.06.006 |access-date= 17 June 2018}}</ref>

<ref name="lcdb">{{cite LCDB|number = 5648 |access-date = 17 June 2018}}</ref>

<ref name="Mottola-2011">{{cite journal |display-authors = 6 |first1 = Stefano |last1 = Mottola |first2 = Mario |last2 = Di Martino |first3 = Anders |last3 = Erikson |first4 = Maria |last4 = Gonano-Beurer |first5 = Albino |last5 = Carbognani |first6 = Uri |last6 = Carsenty |first7 = Gerhard |last7 = Hahn |first8 = Hans-Josef |last8 = Schober |first9 = Felix |last9 = Lahulla |first10 = Marco |last10 = Delbò |first11 = Claes-Ingvar |last11 = Lagerkvist |date = May 2011 |title = Rotational Properties of Jupiter Trojans. I. Light Curves of 80 Objects |journal = The Astronomical Journal |volume = 141 |issue = 5 |page = 32 |bibcode = 2011AJ....141..170M |doi = 10.1088/0004-6256/141/5/170|doi-access= free |url= https://www.openaccessrepository.it/record/99323/files/fulltext.pdf |archive-url= https://web.archive.org/web/20240113171343/https://www.openaccessrepository.it/record/99323/files/fulltext.pdf |url-status= dead |archive-date= 13 January 2024 }}</ref>

<ref name="Waszczak-2016">{{cite journal |display-authors = 6 |first1 = Adam |last1 = Waszczak |first2 = Chan-Kao |last2 = Chang |first3 = Eran O. |last3 = Ofek |first4 = Russ |last4 = Laher |first5 = Frank |last5 = Masci |first6 = David |last6 = Levitan |first7 = Jason |last7 = Surace |first8 = Yu-Chi |last8 = Cheng |first9 = Wing-Huen |last9 = Ip |first10 = Daisuke |last10 = Kinoshita |first11 = George |last11 = Helou |first12 = Thomas A. |last12 = Prince |first13 = Shrinivas |last13 = Kulkarni |date = September 2015 |title = Asteroid Light Curves from the Palomar Transient Factory Survey: Rotation Periods and Phase Functions from Sparse Photometry |journal = The Astronomical Journal |volume = 150 |issue = 3 |page = 35 |bibcode = 2015AJ....150...75W |doi = 10.1088/0004-6256/150/3/75 |arxiv = 1504.04041|s2cid = 8342929 }}</ref>

<ref name="Chatelain-2016">{{Cite journal |first1 = Joseph P. |last1 = Chatelain |first2 = Todd J. |last2 = Henry |first3 = Linda M. |last3 = French |first4 = Jennifer G. |last4 = Winters |first5 = David E. |last5 = Trilling |date = June 2016 |title = Photometric colors of the brightest members of the Jupiter L5 Trojan cloud |journal = Icarus |volume = 271 |pages = 158–169 |bibcode = 2016Icar..271..158C |doi = 10.1016/j.icarus.2016.01.026 |doi-access= free }}</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://www.minorplanetcenter.net/iau/lists/NumberedMPs005001.html Discovery Circumstances: Numbered Minor Planets (5001)-(10000)] – Minor Planet Center * {{AstDys|5648}} * {{JPL small body}}

{{Minor planets navigator |(5647) 1990 TZ |number=5648 |5649 Donnashirley}} {{Small Solar System bodies}} {{Authority control}}

{{DEFAULTSORT:Axius}} 005648 Category:Discoveries by Kin Endate Category:Discoveries by Kazuro Watanabe Category:Named minor planets 19901111