 In this photo taken by theHubble Space Telescope, Namaka is the faint spot near the bottom, directly belowHaumea (center). | |
| Discovery | |
|---|---|
| Discovered by | Michael E. Brown, Chad Trujillo, David Rabinowitz, et al. |
| Discovery date | 30 June 2005 |
| Designations | |
Designation | Haumea II (136108) Haumea II Namaka |
| Pronunciation | /nɑːˈmɑːkə/ Hawaiian:[naːˈmɐkə] |
| (136108) 2003 EL61 II S/2005 (2003 EL61) 2 | |
| Orbital characteristics[1] | |
| EpochJD 2454615.0 | |
| 25657±91 km[1] | |
| Eccentricity | 0.249±0.015 (in 2009;variable) |
| 18.2783±0.0076 d[1] | |
| 178.5°±1.7° | |
| Inclination | 113.013°±0.075° 13.41°±0.08° relative toHiʻiaka (in 2008;variable) |
| 205.016°±0.228° | |
| 178.9°±2.3° | |
| Satellite of | Haumea |
| Physical characteristics | |
| ~85 km (if albedo is same as primary's0.7±0.1) | |
| Mass | (1.79±1.48)×1018kg[1] (0.05% the mass of Haumea) |
Meandensity | (assumed to be near 1 g/cm3) |
| ? | |
| Albedo | 0.8±0.2[2][3] |
| Temperature | 32±3K |
| 21.9 (4.6 difference from primary's 17.3)[2] | |
Namaka is the smaller, inner moon of thetrans-Neptuniandwarf planetHaumea. Discovered in 2005, it is named afterNāmaka, the goddess of the sea inHawaiian mythology and one of the daughters ofHaumea. Namaka is notable for its unusual, highly-perturbed orbit that is heavily influenced by the larger, outer moonHi'iaka.
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.[citation needed]
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 similaralbedo, 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 ofHiʻiaka, the larger moon. Namaka is similar in size toMakemake's moonMK2, 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]
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| Ranked by size | ||
