Namaka (moon)

Smaller moon of Haumea

Namaka

In this photo taken by the Hubble Space Telescope, Namaka is the faint spot near the bottom, directly below Haumea (center).

Discovery
Discovered by| Michael E. Brown,
Chad Trujillo,
David Rabinowitz, et al.
Discovery date| 30 June 2005
Designations

Designation

| Haumea II
Pronunciation| /nɑːˈmɑːkə/
Hawaiian: [naːˈmɐkə]

Alternative names

| (136108) 2003 EL61 II
S/2005 (2003 EL61) 2
Orbital characteristics[1]
Epoch JD 2454615.0

Semi-major axis

| 25657±91 km[1]
Eccentricity| 0.249±0.015 (in 2009; variable)

Orbital period (sidereal)

| 18.2783±0.0076 d[1]

Mean anomaly

| 178.5°±1.7°
Inclination| 113.013°±0.075°
13.41°±0.08° relative to Hiʻiaka (in 2008; variable)

Longitude of ascending node

| 205.016°±0.228°

Argument of perihelion

| 178.9°±2.3°
Satellite of| Haumea
Physical characteristics

Mean radius

| ~85 km (if albedo is same as primary's 0.7±0.1)
Mass| (1.79±1.48)×1018 kg[1]
(0.05% the mass of Haumea)

Mean density

| (assumed to be near 1 g/cm3)

Synodic rotation period

| ?
Albedo| 0.8±0.2[2][3]
Temperature| 32±3 K

Apparent magnitude

| 21.9 (4.6 difference from primary's 17.3)[2]

Namaka is the smaller, inner moon of the trans-Neptunian dwarf planet Haumea. It is named after Nāmaka, the goddess of the sea in Hawaiian mythology and one of the daughters of Haumea.

## Discovery[edit]

Namaka was discovered on 30 June 2005 and announced on 29 November 2005.[4] It was nicknamed "Blitzen" by the discovery team before being assigned an official name.

## Physical characteristics[edit]

Namaka is only 1.5% as bright as its parent dwarf planet Haumea[5] and is about 0.05% its mass. If it turns out to have a similar albedo, it would be about 170 km in diameter.[2] Photometric observations indicate that its surface is made of water ice.[5] Mutual events between 2009 and 2011[6] were expected to improve the knowledge of the orbits and masses of the components of the Haumean system,[3] but interpreting those observations was greatly complicated by the unexpected non-tidally locked spin state of Hiʻiaka, the larger moon. Namaka is similar in size to Makemake's moon MK2, despite being smaller. Further observations of Hiʻiaka might allow to determine its rotation period and spin state more precisely, at which point it should be possible to remove its effect from the data obtained in 2009.[7][8]

## See also[edit]

* Hiʻiaka, the other moon of Haumea

## Notes[edit]

## References[edit]

1. ^ a b c d Ragozzine, D.; Brown, M. E. (2009). "Orbits and Masses of the Satellites of the Dwarf Planet Haumea (2003 EL61)". The Astronomical Journal. 137 (6): 4766–4776. arXiv:0903.4213. Bibcode:2009AJ....137.4766R. doi:10.1088/0004-6256/137/6/4766. S2CID 15310444.
2. ^ a b c Wm. Robert Johnston (17 September 2008). "(136108) Haumea, Hi'iaka, and Nāmaka". Retrieved 18 September 2008.
3. ^ a b Ragozzine, D.; Brown, M. E. (2009). "Orbits and Masses of the Satellites of the Dwarf Planet Haumea (2003 EL61)". The Astronomical Journal. 137 (6): 4766–4776. arXiv:0903.4213. Bibcode:2009AJ....137.4766R. doi:10.1088/0004-6256/137/6/4766. S2CID 15310444.
4. ^ Green, Daniel W. E. (1 December 2005). "IAUC 8636". Retrieved 14 November 2018.
5. ^ a b Barkume, K. M.; Brown, M. E.; Schaller, E. L. (2006). "Water Ice on the Satellite of Kuiper Belt Object 2003 EL61" (PDF). The Astrophysical Journal. 640 (1): L87–L89. arXiv:astro-ph/0601534. Bibcode:2006ApJ...640L..87B. doi:10.1086/503159. S2CID 17831967.
6. ^ Brown, M. "Mutual events of Haumea and Namaka". Retrieved 18 February 2009.
7. ^ Hastings, Danielle M; Ragozzine, Darin; Fabrycky, Daniel C; Burkhart, Luke D; Fuentes, Cesar; Margot, Jean-Luc; Brown, Michael E; Holman, Matthew (2016). "The Short Rotation Period of Hiʻiaka, Haumea's Largest Satellite". The Astronomical Journal. 152 (6): 195. arXiv:1610.04305. Bibcode:2016AJ....152..195H. doi:10.3847/0004-6256/152/6/195. S2CID 33292771.
8. ^ Grundy, W. M; Benecchi, S. D; Rabinowitz, D. L; Porter, S. B; Wasserman, L. H; Skiff, B. A; Noll, K. S; Verbiscer, A. J; Buie, M. W; Tourtellotte, S. W; Stephens, D. C; Levison, H. F (2012). "Mutual Events in the Cold Classical Transneptunian Binary System Sila and Nunam". Icarus. 220 (1): 74–83. arXiv:1204.3923. Bibcode:2012Icar..220...74G. doi:10.1016/j.icarus.2012.04.014. S2CID 16784376.

* v
* t
* e

Moons of likely dwarf planets

| Pluto| Haumea| Eris| Makemake| Gonggong

|
|
|
|

* Charon
* Styx
* Nix
* Kerberos
* Hydra

* ring
* Namaka
* Hiʻiaka

* Dysnomia

* MK2

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| Quaoar| Orcus| Salacia| Varda| 2013 FY27

|
|
|
|

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* 2013 FY27 I

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Haumea

Moons and rings|

* Hiʻiaka
* Namaka
* Rings of Haumea

Collisional family|

* (19308) 1996 TO66
* (24835) 1995 SM55
* (55636) 2002 TX300
* (86047) 1999 OY3
* (120178) 2003 OP32
* (145453) 2005 RR43
* (308193) 2005 CB79
* (386723) 2009 YE7
* (416400) 2003 UZ117
* (612620) 2003 SQ317

Astronomy|

| Discovery|

* Michael E. Brown
* David L. Rabinowitz
* Chad Trujillo
* José Luis Ortiz Moreno
* Controversy

|

Classification|

* Dwarf planet
* Definition of planet
* 2006 definition of planet
* Kuiper belt
* Cubewano
* Trans-Neptunian object

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2002 UX25
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2013 FY27

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