&sq=&lang=&file=File:Nereid-Voyager2.jpg) Nereid imaged by Voyager 2 in 1989 | |
| Discovery[1] | |
|---|---|
| Discovered by | Gerard P. Kuiper |
| Discovery date | 1 May 1949 |
| Designations | |
Designation | Neptune II |
| Pronunciation | /ˈnɪəriəd/ NEER-ee-əd[2] |
Named after | Νηρηΐδες Nērēḯdes |
| Adjectives | Nereidian or Nereidean (both /ˌnɛriˈɪdiən/ NERR-ee-ID-ee-ən)[3] |
| Orbital characteristics[4] | |
| Epoch 1 January 2020 (JD 2458849.5) | |
| Observation arc | 27,601 d (75.57 yr) |
| 5,504,000 km (0.03679 AU) | |
| Eccentricity | 0.749 |
| 360.14 d (0.9860 yr) | |
| 318.0° | |
| 0° 59m 58.597s / day | |
| Inclination | 5.8° (to the ecliptic) 7.090° (to local Laplace plane)[4] |
| 326.0° | |
| 290.3° | |
| Satellite of | Neptune |
| Physical characteristics | |
| 357±13 km[5] | |
| Flattening | ≤0.23[a] |
| Mass | 3.57×1019 kg (5.98×10−6 M🜨) |
Mean density | 1.5 g/cm3 (assumed)[6] |
| ≈0.075 m/s2 (0.0076 g) | |
| 11.594±0.017 h[5] | |
| Albedo | 0.24[5] |
| Temperature | ≈50 K (mean estimate) |
| 19.2[citation needed] | |
| 4.4[7] | |
Nereid, or Neptune II, is the third-largest moon of Neptune. It has the most eccentric orbit of all known moons in the Solar System.[4] It was the second moon of Neptune to be discovered, by Gerard Kuiper in 1949.
- ^ Cite error: The named reference
Kuiper 1949was invoked but never defined (see the help page). - ^ "Nereid". Oxford English Dictionary (Online ed.). Oxford University Press. (Subscription or participating institution membership required.)
- ^ "nereidian, nereidean". Oxford English Dictionary (Online ed.). Oxford University Press. (Subscription or participating institution membership required.)
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