View source for Moons of Haumea

{{short description|Natural satellites orbiting dwarf planet Haumea}}
{{good article}}
{{Use dmy dates|date=July 2019}}
[[File:Haumea-moons-hubble.gif|thumb|Animation of Haumea and its moons, imaged by [[Hubble Space Telescope|Hubble]] in 2008. Hi{{okina}}iaka is the brighter object around Haumea (center), and Namaka is the dimmer object below.]]
[[File:Haumea ring moons diagram.png|thumb|Scale diagram of Haumea, the ring, and orbits of its two moons]]
The [[dwarf planet]] [[Haumea]] has two known [[Natural satellite|moons]], '''[[Hi{{okina}}iaka (moon)|Hi{{okina}}iaka]]''' and '''[[Namaka (moon)|Namaka]]''', named after [[Hawaiian mythology|Hawaiian]] goddesses. These small moons were discovered in 2005, from observations of Haumea made at the large telescopes of the [[W. M. Keck Observatory]] in Hawaii.

Haumea's moons are unusual in a number of ways. They are thought to be part of [[Haumea family|its extended collisional family]], which formed billions of years ago from icy debris after a large impact disrupted Haumea's [[Volatile (astrogeology)|ice]] [[Mantle (geology)|mantle]]. Hi{{okina}}iaka, the larger, outermost moon, has large amounts of pure water ice on its surface, which is rare among [[Kuiper belt]] objects.<ref name="Barkume2006" /> Namaka, about one tenth the mass, has an orbit with surprising dynamics: it is unusually [[Orbital eccentricity|eccentric]] and appears to be greatly influenced by the larger satellite.

== History ==
Two small [[natural satellite|satellites]] were discovered around [[Haumea]] (which was at that time still designated 2003 EL<sub>61</sub>) through observations using the [[W.M. Keck Observatory]] by a [[Caltech]] team in 2005.
The outer and larger of the two satellites was discovered 26 January 2005,<ref>{{cite journal
 |author=M. E. Brown
 |author-link=Michael E. Brown
 |author2=A. H. Bouchez
 |author3=D. Rabinowitz
 |author4=R. Sari
 |author5=C. A. Trujillo
 |author6=M. van Dam
 |author7=R. Campbell
 |author8=J. Chin
 |author9=S. Hardman
 |author10=E. Johansson
|author11=R. Lafon
 |author12=D. Le Mignant
|author13=P. Stomski
 |author14=D. Summers
 |author15=P. Wizinowich
 |title=Keck Observatory Laser Guide Star Adaptive Optics Discovery and Characterization of a Satellite to the Large Kuiper Belt Object 2003 EL61
 |journal=The Astrophysical Journal Letters
 |volume=632|issue=1
 |date=2005-09-02|pages=L45–L48
 |bibcode=2005ApJ...632L..45B
 |doi=10.1086/497641
|s2cid=119408563
 |url=http://authors.library.caltech.edu/34486/1/1538-4357_632_1_L45.pdf
 }}</ref> and formally designated S/2005 (2003 EL<sub>61</sub>) 1, though nicknamed "[[Rudolph the Red-Nosed Reindeer|Rudolph]]" by the Caltech team.<ref>{{cite news
  |author=Kenneth Chang
  |title=Piecing Together the Clues of an Old Collision, Iceball by Iceball
  |url=https://www.nytimes.com/2007/03/20/science/space/20kuip.html
  |work=[[New York Times]]
  |date=2007-03-20
  |access-date=2008-10-12
}}</ref> The smaller, inner satellite of Haumea was discovered on 30 June 2005, formally termed S/2005 (2003 EL<sub>61</sub>) 2, and nicknamed "[[Blitzen the Reindeer|Blitzen]]".<ref name="RagozzineDPS08" /> On 7 September 2006, both satellites were numbered and admitted into the official minor planet catalogue as (136108) 2003 EL<sub>61</sub> I and II, respectively.

The permanent names of these moons were announced, together with that of 2003 EL<sub>61</sub>, by the [[International Astronomical Union]] on 17 September 2008: (136108) Haumea I Hi{{okina}}iaka and (136108) Haumea II Namaka.<ref name="iaunews">{{cite web
 |title=News Release – IAU0807: IAU names fifth dwarf planet Haumea
 |work=International Astronomical Union
 |date=2008-09-17
 |url=http://www.iau.org/public_press/news/release/iau0807/
 |access-date=2008-09-18
}}</ref> Each moon was named after a daughter of [[Haumea (mythology)|Haumea]], the Hawaiian goddess of fertility and childbirth. [[Hi{{okina}}iaka]] is the goddess of [[hula|dance]] and patroness of the [[Big Island of Hawaii]], where the [[Mauna Kea Observatory]] is located.<ref name="usgs">{{cite news
  |publisher=US Geological Survey Gazetteer of Planetary Nomenclature
  |title=Dwarf Planets and their Systems
  |url=http://planetarynames.wr.usgs.gov/append7.html#DwarfPlanets
  |access-date=2008-09-17
}}</ref> [[Nāmaka]] is the goddess of water and the sea; she cooled her sister [[Pele (deity)|Pele]]'s lava as it flowed into the sea, turning it into new land.<ref name="craig" />

In her legend, Haumea's many children came from different parts of her body.<ref name="craig">{{cite book
 |author=Robert D. Craig
 |title=Handbook of Polynesian Mythology
 |publisher=ABC-CLIO
 |date=2004
 |url=https://books.google.com/books?id=LOZuirJWXvUC&q=haumea&pg=PA128
 |page=128
 |isbn=1-57607-894-9
}}</ref> The dwarf planet [[Haumea]] appears to be almost entirely made of rock, with only a superficial layer of ice; most of the original icy mantle is thought to have been blasted off by the impact that spun Haumea into its current high speed of rotation, where the material formed into the small [[Kuiper belt]] objects in [[Haumea family|Haumea's collisional family]]. There could therefore be additional outer moons, smaller than Namaka, that have not yet been detected. However, [[Hubble Space Telescope|HST]] observations have confirmed that no other moons brighter than 0.25% of the brightness of Haumea exist within the closest tenth of the distance (0.1% of the volume) where they could be held by Haumea's gravitational influence (its [[Hill sphere]]).<ref name="Ragozzine&Brown2009">{{cite journal
 |last=Ragozzine |first=D.
 |author2=Brown, M.E.
 |date=2009
 |title=Orbits and Masses of the Satellites of the Dwarf Planet Haumea = 2003 EL61
 |journal=The Astronomical Journal
 |arxiv=0903.4213
 |bibcode = 2009AJ....137.4766R
 |doi = 10.1088/0004-6256/137/6/4766
 |volume=137
 |issue=6
 |pages=4766–4776
|s2cid=15310444
 }}</ref> This makes it unlikely that any more exist.

== Surface properties ==
[[File:Haumea Hubble.png|thumb|[[Hubble Space Telescope|Hubble]] image of Haumea (center), Hi{{okina}}iaka (above), and Namaka (below).]]
Hi{{okina}}iaka is the outer and, at roughly 310&nbsp;km in diameter, the larger and brighter of the two moons.<ref name="Brown2006-discovery">{{cite journal| doi = 10.1086/501524| last1 = Brown| first1 = M. E.| author-link = Michael E. Brown| last2 = Van Dam| first2 = M. A.| last3 = Bouchez| first3 = A. H.| last4 = Le Mignant| first4 = D.| last5 = Campbell| first5 = R. D.| last6 = Chin| first6 = J. C. Y.| last7 = Conrad| first7 = A.| last8 = Hartman| first8 = S. K.| last9 = Johansson| first9 = E. M.| last10 = Lafon| first10 = R. E.| last11 = Rabinowitz| first11 = D. L. Rabinowitz| last12 = Stomski| first12 = P. J. Jr.| last13 = Summers| first13 = D. M.| last14 = Trujillo| first14 = C. A.| last15 = Wizinowich| first15 = P. L.| year = 2006| title = Satellites of the Largest Kuiper Belt Objects| journal = The Astrophysical Journal| volume = 639| issue = 1| pages = L43–L46| arxiv = astro-ph/0510029| bibcode = 2006ApJ...639L..43B| s2cid = 2578831| url = http://web.gps.caltech.edu/~mbrown/papers/ps/gab.pdf| access-date = 19 October 2011| ref = {{sfnRef|Brown Van Dam et al.|2006}}
}}</ref> Strong absorption features observed at 1.5, 1.65 and 2 [[micrometre|μm]] in its [[infrared]] spectrum are consistent with nearly pure crystalline water ice covering much of its surface. The unusual spectrum, and its similarity to absorption lines in the spectrum of Haumea, led Brown and colleagues to conclude that it was unlikely that the system of moons was formed by the gravitational capture of passing Kuiper belt objects into orbit around the dwarf planet: instead, the Haumean moons must be fragments of Haumea itself.<ref name="largest">{{cite web
 |title=The largest Kuiper belt objects
 |author=Michael E. Brown
 |work=Caltech
 |url=http://www.gps.caltech.edu/~mbrown/papers/ps/kbochap.pdf
 |access-date=2008-09-19
}}</ref>

The sizes of both moons are calculated with the assumption that they have the same infrared [[albedo]] as Haumea, which is reasonable as their spectra show them to have the same surface composition. Haumea's albedo has been measured by the [[Spitzer Space Telescope]]: from ground-based telescopes, the moons are too small and close to Haumea to be seen independently.<ref name="Fraser09" /> Based on this common albedo, the inner moon, Namaka, which is a tenth the mass of Hi{{okina}}iaka, would be about 170&nbsp;km in diameter.<ref name="Johnston">{{cite web
 |url=http://www.johnstonsarchive.net/astro/astmoons/am-136108.html
 |title=(136108) Haumea, Hi'iaka, and Namaka
 |publisher=Johnstonsarchive.net
 |access-date=2009-02-01
}}</ref>

The [[Hubble Space Telescope]] (HST) has adequate angular resolution to separate the light from the moons from that of Haumea. Photometry of the Haumea triple system with HST's [[Near Infrared Camera and Multi-Object Spectrometer|NICMOS camera]] has confirmed that the spectral line at 1.6&nbsp;μm that indicates the presence of water ice is at least as strong in the moons' spectra as in Haumea's spectrum.<ref name="Fraser09">{{cite journal
 |last=Fraser  |first=W.C.
 |author2=Brown, M.E.
 |date=2009
 |title=NICMOS Photometry of the Unusual Dwarf Planet Haumea and its Satellites
 |journal=The Astrophysical Journal Letters
 |volume=695  |issue=1
 |pages=L1–L3
 |arxiv=0903.0860
 |bibcode=2009ApJ...695L...1F
 |doi=10.1088/0004-637X/695/1/L1
|s2cid=119273925
 }}</ref>

The moons of Haumea are too faint to detect with telescopes smaller than about 2 metres in [[aperture]], though Haumea itself has a visual magnitude of 17.5, making it the third-brightest object in the Kuiper belt after [[Pluto]] and [[Makemake]], and easily observable with a large amateur telescope.

== Orbital characteristics ==
{{multiple image |direction=vertical |align=right |total_width=300
 |image1=TheKuiperBelt Orbits Haumea moons.svg |caption1=A view of the orbits of Hi{{okina}}iaka (blue) and Namaka (green)
 |image2=Haumea mutual events illustration.png |caption2=Illustration of mutual events between Haumea and Namaka during 2009–2011
}}
Hi{{okina}}iaka orbits Haumea nearly circularly every 49&nbsp;days.<ref name="Brown2006-discovery" /> Namaka orbits Haumea in 18 days in a moderately elliptical, [[Osculating orbit|non-Keplerian]] orbit, and as of 2008 was inclined 13° with respect to Hi{{okina}}iaka, which [[Perturbation (astronomy)|perturbs]] its orbit.<ref name="RagozzineDPS08" /> Because the impact that created the moons of Haumea is thought to have occurred in the early history of the Solar System,<ref name="BrownBarkume2007">{{cite journal
 |author=Michael E. Brown |author2= Kristina M. Barkume |author3=Darin Ragozzine |author4=Emily L. Schaller
 |date=2007-01-19
 |title=A collisional family of icy objects in the Kuiper belt
 |journal=Nature
 |volume=446 |issue=7133 |pages=294–296
 |doi=10.1038/nature05619
 |pmid=17361177
 |bibcode = 2007Natur.446..294B
|s2cid= 4430027 |url= https://authors.library.caltech.edu/34346/2/nature05619-s1.pdf }}</ref> over the following billions of years it should have been [[tidal acceleration|tidally damped]] into a more circular orbit. Namaka's orbit has likely been disturbed by [[orbital resonance]]s with the more-massive Hi{{okina}}iaka due to converging orbits as they moved outward from Haumea due to [[tidal acceleration|tidal dissipation]].<ref name="RagozzineDPS08" /> They may have been caught in and then escaped from orbital resonance several times; they currently are in or at least close to an 8:3 [[orbital resonance|resonance]].<ref name="RagozzineDPS08" /> This resonance strongly perturbs Namaka's orbit, which has a current [[Apsidal precession|precession]] of its [[argument of periapsis]] by about −6.5° per year, a precession period of 55 years.<ref name="Ragozzine&Brown2009" />

From around 2008 to 2011,<ref>{{cite journal |last1=Dumas |first1=C. |last2=Carry |first2=B. |first3=D. |last3=Hestroffer |first4=F. |last4=Merlin |date=2011 |title=High-contrast observations of (136108) Haumea |url=https://www.aanda.org/articles/aa/full_html/2011/04/aa15011-10/aa15011-10.html |journal=Astronomy & Astrophysics |volume=528 |issue= |pages= A105|doi=10.1051/0004-6361/201015011 |access-date=24 August 2024|arxiv=1101.2102 |bibcode=2011A&A...528A.105D }}</ref> the orbits of the Haumean moons appeared almost exactly edge-on from Earth, with Namaka periodically [[occultation|occulting]] Haumea.<ref name="IAU8949">{{cite web
 |url         = http://www.cfa.harvard.edu/~fabrycky/EL61/
 |title       = IAU Circular 8949
 |date        = 17 September 2008
 |publisher   = International Astronomical Union
 |access-date  = 2008-12-06
 |url-status     = dead
 |archive-url  = https://web.archive.org/web/20090111105134/http://www.cfa.harvard.edu/~fabrycky/EL61/
 |archive-date = 11 January 2009
 |df          = dmy-all
}}</ref><ref name="events09">{{cite web
  |url=http://web.gps.caltech.edu/~mbrown/2003EL61/mutual/
  |title=Mutual events of Haumea and Namaka
  |author=Brown, M.
  |access-date=2009-02-18
}}</ref> Observation of such transits would have provided precise information on the size and shape of Haumea and its moons,<ref name="events09"/> as happened in [[Solar eclipses on Pluto|the late 1980s with Pluto and Charon]].<ref>{{cite book
  |author=Lucy-Ann Adams McFadden |author2=Paul Robert Weissman |author3=Torrence V. Johnson
  |title=Encyclopedia of the Solar System
  |url=https://books.google.com/books?id=G7UtYkLQoYoC&q=mutual+event+pluto&pg=PA545
  |access-date=2008-10-17
  |isbn=978-0-12-088589-3
  |date=2007
|publisher=Elsevier }}</ref> The tiny change in brightness of the system during these occultations would have required at least a [[Optical telescope#Optical Research telescopes|medium]]-[[aperture]] [[List of optical telescopes|professional telescope]] for detection.<ref name="events09" /><ref name="FabryckyDPS08">{{cite journal |author=D. C. Fabrycky |display-authors=4 |author2=M. J. Holman |author3=D. Ragozzine |author4=M. E. Brown |author5=T. A. Lister |author6=D. M. Terndrup |author7=J. Djordjevic |author8=E. F. Young |author9=L. A. Young |author10=R. R. Howell |title=Mutual Events of 2003 EL61 and its Inner Satellite |pages=36.08 |journal=AAS DPS Conference 2008 |bibcode=2008DPS....40.3608F |year=2008 |volume=40 }}</ref> Hi{{okina}}iaka last occulted Haumea in 1999, a few years before discovery, and will not do so again for some 130 years.<ref name="shadows">{{cite web
  |title=Moon shadow Monday (fixed)
  |author=Mike Brown
  |date=2008-05-18
  |publisher=Mike Brown's Planets
  |url=http://www.mikebrownsplanets.com/2008/05/moon-shadow-monday-fixed.html
  |access-date=2008-09-27
}}</ref> However, in a situation unique among [[regular moon|regular satellites]], Namaka's orbit was being greatly [[Apsidal precession|torqued]] by Hi{{okina}}iaka, which preserved the viewing angle of Namaka–Haumea transits for several more years.<ref name="RagozzineDPS08">{{cite web
 |author      = D. Ragozzine
 |author2     = M. E. Brown
 |author3     = C. A. Trujillo
 |author4     = E. L. Schaller
 |title       = Orbits and Masses of the 2003 EL61 Satellite System
 |url         = http://www.abstractsonline.com/viewer/viewAbstract.asp?CKey={421E1C09-F75A-4ED0-916C-8C0DDB81754D}&MKey={35A8F7D5-A145-4C52-8514-0B0340308E94}&AKey={AAF9AABA-B0FF-4235-8AEC-74F22FC76386}&SKey={545CAD5F-068B-4FFC-A6E2-1F2A0C6ED978}
 |work        = AAS DPS conference 2008
 |access-date  = 17 October 2008
 |url-status     = dead
 |archive-url  = https://web.archive.org/web/20130718182107/http://www.abstractsonline.com/viewer/viewAbstract.asp?CKey=%7B421E1C09-F75A-4ED0-916C-8C0DDB81754D%7D&MKey=%7B35A8F7D5-A145-4C52-8514-0B0340308E94%7D&AKey=%7BAAF9AABA-B0FF-4235-8AEC-74F22FC76386%7D&SKey=%7B545CAD5F-068B-4FFC-A6E2-1F2A0C6ED978%7D
 |archive-date = 18 July 2013
 |df          = dmy-all
}}</ref><ref name="events09" /><ref name="FabryckyDPS08" /> One occultation event was observed on 19 June 2009, from the [[Pico dos Dias Observatory]] in Brazil.<ref>{{cite journal |last1=Bortoletto |first1=A. |last2=Saito |first2=R. K. |date=2010 |title=Observing mutual events of the trans-Neptunian object Haumea and Namaka from Brazil |url=https://articles.adsabs.harvard.edu//full/2010IAUS..269..189B/0000189.000.html |journal=Proceedings of the International Astronomical Union |volume=269 |issue= |pages=189–192 |bibcode=2010IAUS..269..189B |doi= 10.1017/S1743921310007404|access-date=24 August 2024}}</ref><!--article text says 16th but figure says 19th. Probably 19th, since Mike Brown's site confirms occultation was on the 19th-->

{| class="wikitable"  style="margin:1em auto;" border="1"
|- style="background:#efefef;"
! Label <br />{{refn| group = note | Label refers to the [[Roman numerals|Roman numeral]] attributed to each moon in order of their discovery.<ref name="Gazetteer">{{Cite web|title=Planet and Satellite Names and Discoverers|work=Gazetteer of Planetary Nomenclature|publisher=USGS Astrogeology|url=https://planetarynames.wr.usgs.gov/Page/Planets|access-date=2022-06-23}}</ref>}}
! colspan="2" | Name<br />([[Help:IPA for English|pronunciation]])
! Mean diameter<br />(km)
! Mass<br />(×10<sup>18</sup>&nbsp;kg)
! Semi-major<br />axis (km)
! Orbital period<br />(days)
! Eccentricity
! Inclination (°){{refn | group = note |Orbital inclinations of Namaka and Hi{{okina}}iaka are with respect to Haumea's orbit.<!-- Axial tilt of Haumea equals ≈ 126° to Haumea's orbit and 81.2° or 78.9° to [[ecliptic]]. Usually inclinations of regular satellites are in the plane of primary body rotation. -->}}
! Discovery date
|- style="text-align:center; background:white;"
| 
| colspan="2" | (ring) || ≈&thinsp;70 || || {{val|2285|8}}<ref name="Ortiz2017" /> || {{val|0.489438|0.000012}}<ref name="Ortiz2017">{{cite journal|display-authors= 3|last1= Ortiz|first1=J. L.|last2= Santos-Sanz|first2=P.|last3= Sicardy|first3= B.|last4= Benedetti-Rossi|first4= G.|last5= Bérard|first5= D.|last6= Morales|first6= N.|last7= Duffard|first7= R.|last8= Braga-Ribas|first8=F.|last9= Hopp|first9=U.|last10= Ries|first10=C.|last11= Nascimbeni|first11=V.|last12= Marzari|first12=F.|last13= Granata|first13=V.|last14= Pál|first14=A.|last15= Kiss|first15=C.|last16= Pribulla|first16=T.|last17=Komžík|first17=R.|last18= Hornoch|first18=K.|last19=Pravec|first19=P.|last20= Bacci|first20=P.|last21= Maestripieri|first21= M.|last22= Nerli|first22=L.|last23=Mazzei|first23=L.|last24= Bachini|first24=M.|last25=Martinelli|first25= F.|last26=Succi|first26= G.|last27=Ciabattari|first27=F.|last28= Mikuz|first28=H.|last29=Carbognani|first29= A.|last30=Gaehrken|first30=B.|last31= Mottola|first31=S.|last32= Hellmich|first32=S.|last33=Rommel|first33=F. L.|last34=Fernández-Valenzuela|first34=E.|last35= Bagatin|first35=A. Campo|last36=Cikota|first36= S.|last37=Cikota|first37=A.|last38=Lecacheux|first38=J.|last39=Vieira-Martins|first39=R.|last40=Camargo|first40=J. I. B.|last41=Assafin|first41=M.|last42= Colas|first42=F.|last43=Behrend|first43= R.|last44=Desmars|first44=J.|last45=Meza|first45=E.|last46=Alvarez-Candal|first46=A.|last47=Beisker|first47=W.|last48= Gomes-Junior|first48=A. R.|last49= Morgado|first49=B. E.|last50=Roques|first50=F.|last51= Vachier|first51=F.|last52=Berthier|first52= J.|last53=Mueller|first53=T. G.|last54=Madiedo|first54=J. M.|last55=Unsalan|first55=O.|last56= Sonbas|first56=E.|last57=Karaman|first57= N.|last58=Erece|first58=O.|last59=Koseoglu|first59=D. T.|last60=Ozisik|first60=T.|last61= Kalkan|first61=S.|last62= Guney|first62=Y.|last63=Niaei|first63=M. S.|last64=Satir|first64=O.|last65= Yesilyaprak|first65=C.|last66= Puskullu|first66=C.|last67=Kabas|first67= A.|last68=Demircan|first68= O.|last69=Alikakos|first69=J.|last70= Charmandaris|first70=V.|last71=Leto|first71=G.|last72=Ohlert|first72=J.|last73=Christille|first73=J. M.|last74=Szakáts|first74=R.|last75=Farkas|first75=A. Takácsné|last76=Varga-Verebélyi|first76=E.|last77= Marton|first77=G.|last78=Marciniak|first78= A.|last79=Bartczak|first79=P.|last80=Santana-Ros|first80=T.|last81=Butkiewicz-Bąk|first81=M.|last82=Dudziński|first82=G.|last83=Alí-Lagoa|first83=V.|last84= Gazeas|first84=K.|last85= Tzouganatos|first85=L.|last86=Paschalis|first86=N.|last87=Tsamis|first87=V.|last88=Sánchez-Lavega|first88=A.|last89=Pérez-Hoyos|first89=S.|last90= Hueso|first90=R.|last91=Guirado|first91=J. C.|last92=Peris|first92=V.|last93=Iglesias-Marzoa|first93=R.|title=The size, shape, density and ring of the dwarf planet Haumea from a stellar occultation|journal= Nature|volume= 550|issue= 7675|year= 2017|pages= 219–223|doi= 10.1038/nature24051|pmid= 29022593|arxiv= 2006.03113|bibcode=2017Natur.550..219O|hdl= 10045/70230|s2cid= 205260767|hdl-access=free}}</ref><ref name="ring-period" group=lower-alpha>Based on a 3:1 resonance with Haumea's rotation period.</ref> || || [approximately same as Haumea's equator] || January 2017
|- style="text-align:center; background:white;"
| II || '''[[Namaka (moon)|Namaka]]''' || {{IPA|/nɑːˈmɑːkə/}} || ≈&thinsp;170? || {{val|1.79|1.48}}<ref name="Ragozzine&Brown2009" /> <br />(≈&thinsp;0.05% Haumea) || {{val|25657|91}}<ref name="Ragozzine&Brown2009" />|| {{val|18.2783|0.0076}}<ref name="Ragozzine&Brown2009" /><ref group=note name=kepler>Using [[Kepler's laws of planetary motion#Third law|Kepler's third law]].</ref> || {{val|0.249|0.015}}<ref name="Ragozzine&Brown2009" /><ref group=note name=perturb>As of 2008: Namaka's eccentricity and inclination are [[Kozai mechanism|variable]] due to perturbation.</ref> || {{val|113.013|0.075}}<ref name="Ragozzine&Brown2009" /> <br />({{val|13.41|0.08}} from Hi{{okina}}iaka)<ref group=note name=perturb />|| June 2005
|- style="text-align:center; background:white;"
| I || '''[[Hi{{okina}}iaka (moon)|Hi{{okina}}iaka]]''' || {{IPA|/hiːʔiːˈɑːkə/}} || ≈&thinsp;310 || {{val|17.9|1.1}}<ref name="Ragozzine&Brown2009" /> <br />(≈&thinsp;0.5% Haumea) || {{val|49880|198}}<ref name="Ragozzine&Brown2009" /> || {{val|49.462|0.083}}<ref name="Ragozzine&Brown2009" /><ref group=note name=kepler /> || {{val|0.0513|0.0078}}<ref name="Ragozzine&Brown2009" /> || {{val|126.356|0.064}}<ref name="Ragozzine&Brown2009" /> || January 2005
|}

== Notes ==
{{reflist
| group = note
}}
{{notelist}}

== References ==
{{Reflist|30em| refs =
<ref name="Barkume2006">{{Cite journal | last1 = Barkume | first1 = K. M. | last2 = Brown | first2 = M. E. | last3 = Schaller | first3 = E. L. | title = Water Ice on the Satellite of Kuiper Belt Object 2003 EL61 | doi = 10.1086/503159 | journal = The Astrophysical Journal | volume = 640 | issue = 1 | pages = L87–L89 | year = 2006 | url = http://www.gps.caltech.edu/~mbrown/papers/ps/rudolph.pdf|arxiv = astro-ph/0601534 |bibcode = 2006ApJ...640L..87B | s2cid = 17831967 }}</ref>
}}

== External links ==
* [https://web.archive.org/web/20090327050619/http://www.gps.caltech.edu/~darin/haumeasatsanim.gif Animation of the orbits of Haumea's moons]
* [[International Year of Astronomy]] 2009 [http://365daysofastronomy.org/2009/03/31/march-31st/ podcast: Dwarf Planet Haumea (Darin Ragozzine)]
* [http://www.gps.caltech.edu/%7Embrown/papers/ps/EL61.pdf Brown's publication describing the discovery of Hi{{okina}}iaka]
* [http://www.gps.caltech.edu/~mbrown/papers/ps/rudolph.pdf Paper describing the composition of Hi{{okina}}iaka]

{{Moons of plutoids}}
{{Haumea}}
{{Solar System moons (compact)}}
{{Solar System}}

[[Category:Moons of Haumea| ]]
[[Category:Lists of moons]]
[[Category:Solar System]]