View source for S/2003 J 2

{{Short description|Moon of Jupiter that comes after Praxidike}}
{{Infobox planet
| name            = S/2003 J 2
| image           = 2003 J 2 Gladman CFHT annotated.gif
| image_scale      =
| caption         = S/2003 J 2 imaged by the [[Canada-France-Hawaii Telescope]] during follow-up observations in February 2003
| discovery_ref   = &thinsp;<ref name="MPEC-2003-E11"/>
| discoverer      = [[Scott S. Sheppard]] et al.
| discovery_site  = [[Mauna Kea Observatory|Mauna Kea Obs.]]
| discovered      = 5 February 2003
| orbit_ref       = &thinsp;<ref name="MPEC-2021-B134"/>
| epoch           = 17 December 2020 ([[Julian day|JD]] 2459200.5)
| observation_arc = 16.42 [[Julian year (astronomy)|yr]] (5,996 [[day|d]])
| earliest_precovery_date = 11 December 2001
| semimajor       = {{cvt|0.1373976|AU|km|lk=in}}
| eccentricity    = 0.2776569
| period          = –1.65 yr (–602.02 d)
| mean_anomaly    = 114.43587[[Degree (angle)|°]]
| mean_motion     = {{Deg2DMS|0.59798394|sup=ms}} / day
| inclination     = 149.20392° {{small|(to [[ecliptic]])}}
| asc_node        = 50.46976°
| arg_peri        = 224.95527°
| satellite_of    = [[Jupiter]]
| group           = [[Ananke group]]
| mean_diameter   = ≈{{val|2|u=km}}<ref name="SheppardMoons"/>
| rotation        = 
| albedo          = 0.04 {{small|(assumed)}}<ref name="SheppardMoons"/>
| magnitude       = 23.2<ref name="SheppardMoons"/>
| abs_magnitude   = 16.7<ref name="MPEC-2021-B134"/>
}}

'''{{nowrap|S/2003 J 2}}''' is a [[retrograde motion|retrograde]] [[irregular satellite]] of [[Jupiter]]. The moon was discovered on 5 February 2003 by a team of astronomers from the [[University of Hawaii at Manoa|University of Hawaii]] led by [[Scott S. Sheppard]] and [[David C. Jewitt]], and was later announced on 4 March 2003.<ref>[http://www.cbat.eps.harvard.edu/iauc/08000/08087.html IAUC 8087: ''Satellites of Jupiter''] 2003 March 4 (discovery)</ref><ref name="SheppardJewitt2003">{{cite journal|last=Sheppard |first=Scott S. |author2=Jewitt, David C. |year=2003 |title=An abundant population of small irregular satellites around Jupiter |journal=[[Nature (journal)|Nature]] |volume=423 |issue=6937 |pages=261&ndash;263 |doi=10.1038/nature01584 |url=http://www.ifa.hawaii.edu/~jewitt/papers/JSATS/SJ2003.pdf |pmid=12748634 |url-status=dead |archive-url=https://web.archive.org/web/20060515044537/http://www.ifa.hawaii.edu/~jewitt/papers/JSATS/SJ2003.pdf |archive-date=May 15, 2006 |bibcode = 2003Natur.423..261S |s2cid=4424447 }}</ref> It was initially thought to be Jupiter's outermost known moon until recovery observations disproved this in 2020.<ref name="Hecht2020">{{cite web |url=https://skyandtelescope.org/astronomy-news/amateur-astronomer-finds-lost-moons-of-jupiter/ |title=Amateur Astronomer Finds "Lost" Moons of Jupiter |last=Hecht |first=Jeff |date=2021-01-11 |website=www.skyandtelescope.com |publisher=Sky & Telescope |access-date=2021-01-11}}</ref>

{{nowrap|S/2003 J 2}} is about {{convert|2|km|mi|abbr=on}} in diameter, and orbits Jupiter at an average distance of about {{convert|20,600,000|km|AU|lk=on}} in roughly 600 days, at an [[inclination]] of around 149° to the [[ecliptic]] and with an [[eccentricity (orbit)|eccentricity]] of 0.28. The moon was initially assumed to be part of the [[Pasiphae group]], but is now known to be part of the [[Ananke group]] after it was recovered in 2020.<ref name="MPEC-2003-E11">[http://www.minorplanetcenter.net/mpec/K03/K03E11.html MPEC 2003-E11: ''S/2003 J 1, 2003 J 2, 2003 J 3, 2003 J 4, 2003 J 5, 2003 J 6, 2003 J 7''] 2003 March 4 (discovery and ephemeris)</ref><ref name="Hecht2020"/>

[[File:2003 J 2 CFHT 2003-04-30.gif|thumb|left|S/2003 J 2 and several bright background stars and galaxies imaged by the CFHT in April 2003]]

The moon was considered [[lost asteroid|lost]]<ref>{{cite web |url=http://www.skyandtelescope.com/astronomy-news/outer-planet-moons-found-and-lost/ |title=Outer-Planet Moons Found — and Lost |last=Beatty |first=Kelly |date=4 April 2012 |website=www.skyandtelescope.com |publisher=Sky & Telescope |access-date=27 June 2017}}</ref><ref name=Jacobson>{{cite journal |last1=Brozović |first1=Marina |last2=Jacobson |first2=Robert A. |date=9 March 2017 |title=The Orbits of Jupiter's Irregular Satellites |journal=The Astronomical Journal |volume=153 |issue=4 |pages=147 |doi=10.3847/1538-3881/aa5e4d|bibcode = 2017AJ....153..147B |doi-access=free }}</ref><ref>{{cite journal |last1=Jacobson |first1=B. |last2=Brozović |first2=M. |first3=B. |last3=Gladman |first4=M. |last4=Alexandersen |first5=P. D. |last5=Nicholson |first6=C. |last6=Veillet |date=28 September 2012 |title=Irregular Satellites of the Outer Planets: Orbital Uncertainties and Astrometric Recoveries in 2009–2011 |journal=The Astronomical Journal |volume=144 |issue=5 |pages=132 |doi=10.1088/0004-6256/144/5/132 |bibcode = 2012AJ....144..132J |s2cid=123117568 |doi-access=free }}</ref><ref>{{cite web |url=http://home.dtm.ciw.edu/users/sheppard/satellites/jup2017.html |title=New Moons of Jupiter Announced in 2017 |last=Sheppard |first=Scott S. |date=2017 |website=home.dtm.ciw.edu |access-date=27 June 2017 |quote=We likely have all of the lost moons in our new observations from 2017, but to link them back to the remaining lost 2003 objects requires more observations a year later to confirm the linkages, which will not happen until early 2018. ...  There are likely a few more new moons as well in our 2017 observations, but we need to reobserve them in 2018 to determine which of the discoveries are new and which are lost 2003 moons. |archive-date=10 June 2017 |archive-url=https://web.archive.org/web/20170610075918/http://home.dtm.ciw.edu/users/sheppard/satellites/jup2017.html |url-status=dead }}</ref> until 2020, when it was recovered by Sheppard and independently by amateur astronomer Kai Ly.<ref name="Hecht2020"/> The recovery of the moon was announced by the [[Minor Planet Center]] on 26 January 2021.<ref name="MPEC-2021-B134"/>
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==References==
<references>
<ref name="SheppardMoons">[https://sites.google.com/carnegiescience.edu/sheppard/moons/jupitermoons S.S. Sheppard (2019), Moons of Jupiter, ''Carnegie Science'', on line]</ref>

<ref name="MPEC-2021-B134">{{cite web
  |title      = MPEC 2021-B134 : S/2003 J 2
  |url        = https://minorplanetcenter.net/mpec/K21/K21BD4.html
  |work       = Minor Planet Electronic Circular
  |publisher  = Minor Planet Center
  |date       = 26 January 2021
  |accessdate = 26 January 2021}}</ref>
</references>


{{Moons of Jupiter}}

{{DEFAULTSORT:S 2003 J 2}}
[[Category:Moons of Jupiter]]
[[Category:Irregular satellites]]
[[Category:Astronomical objects discovered in 2003|20030305]]
[[Category:Ananke group]]
[[Category:Discoveries by Scott S. Sheppard]]
[[Category:Moons with a retrograde orbit]]
[[Category:Recovered astronomical objects]]