S/2003 J 4

{{Short description|Moon of Jupiter}}

{{Infobox planet

| name = S/2003 J 4

| image = 2003 J 4 Gladman CFHT annotated.gif

| image_scale =

| caption = S/2003 J 4 imaged by the Canada-France-Hawaii Telescope during follow-up observations in February 2003

| discovery_ref =  

| discoverer = Scott S. Sheppard et al.

| discovery_site = Mauna Kea Obs.

| discovered = 5 February 2003

| orbit_ref =  

| epoch = 17 December 2020 (JD 2459200.5)

| observation_arc = 16.42 yr (5,997 d)

| earliest_precovery_date = 10 December 2001

| semimajor = {{cvt|0.1473856|AU|km|lk=in}}

| eccentricity = 0.4967418

| period = –1.83 yr (–668.85 d)

| mean_anomaly = 146.33793°

| mean_motion = {{Deg2DMS|0.53824008|sup=ms}} / day

| inclination = 149.40138° {{small|(to ecliptic)}}

| asc_node = 249.91700°

| arg_peri = 240.54004°

| satellite_of = Jupiter

| group = Pasiphae group

| mean_diameter = ≈{{val|2|u=km}}

| rotation =

| albedo = 0.04 {{small|(assumed)}}

| magnitude = 23.0

| abs_magnitude = 16.7

}}

{{nowrap|S/2003 J 4}} is a natural satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S. Sheppard in 2003.[http://cbat.eps.harvard.edu/iauc/08000/08087.html IAUC 8087: Satellites of Jupiter] 2003 March 4 (discovery)[https://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)

{{nowrap|S/2003 J 4}} is about 2 km in diameter, and orbits Jupiter at an average distance of 23,000,000 km in 669 days, at an inclination of 149° to the ecliptic, in a retrograde direction and with an eccentricity of 0.497.

It belongs to the Pasiphae group, irregular retrograde moons orbiting Jupiter at distances ranging between 22.8 and 24.1 Gm, and with inclinations ranging between 144.5° and 158.3°.

This moon was considered lost{{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}}{{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 }}{{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 }}{{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.}} until late 2020, when it was recovered by amateur astronomers Kai Ly and Sam Deen in archival images from 2001-2018.{{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}} The recovery of the moon was announced by the Minor Planet Center on 13 January 2021.

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