User:Eurocommuter/test4
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| Discovery [1] | |
|---|---|
| Discovered by | S. Sheppard, D. Jewitt and J. Kleyna |
| Discovered | in September 2003 |
| provisional designation |
S/2003 N1 |
| Mean Orbital elements [2] | |
| Semi-major axis | 46,695,000 km |
| Eccentricity | 0.4499 |
| Inclination | 137° * |
| Orbital period | 9115 d (24.96 yr) |
| Physical characteristics | |
| Mean diameter | 28 km [2] ** |
| Rotation period | ? |
| Albedo | 0.04 assumed[2] |
| color | light red B-V=0.60 V-R=0.45[3] |
| spectral type | D [4] |
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|
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| *to the ecliptic | **based on the albedo |
Psamathe (sam'-ə-thee, IPA: [ʼsæməθi], Latin Psamathē from Greek Ψαμάθη) or Neptune X, is a retrograde irregular satellite of Neptune.
Psamathe was discovered by S.Sheppard, D. Jewiit and J. Kleyna in September 2003. They reported a satellite which proved to be the same as one of the moons also observed by M. Holman and given the provisional designation S/2003 N 1.[5]
It is named after Psamathe, one of the Nereids.
Psamathe orbits Neptune at a distance of about 46.7 Gm and remarkably takes almost 25 Earth years to make one orbit. It's diameter is estimated at 28 kilometers, assuming albedo of 0.04.
The diagram illustrates its orbit in relation to other irregular satellites of Neptune. The eccentricity of selected orbits is represented by the yellow segments (extending from the pericentre to the apocentre).
Given the similarity of the orbit's parameters with S/2002 N 4, it was suggested that both irregular satellites could have a common origin in the break-up of a larger moon.[2]
[edit] See also
[edit] External links
[edit] References
- ^ Discovery Circumstances (JPL)
- ^ a b c d S. Sheppard, D. Jewitt, J. Kleyna A Survey for "Normal" Irregular Satellites Around Neptune: Limits to Completeness, The Astronomical Journal, 132 (2006), pp. 171–176. Preprint.
- ^ Grav, Tommy; Holman, Matthew J.; Gladman, Brett J.; Aksnes, Kaare Photometric survey of the irregular satellites,Icarus, 166,(2003), pp. 33-45. Preprint
- ^ Tommy Grav and Matthew J. Holman Near-Infrared Photometry of the Irregular Satellites of Jupiter and Saturn,The Astrophysical Journal, 605, (2004), pp. L141–L144 Preprint
- ^ M. Holman, JJ Kavelaars, B. Gladman, Grav, Tommy; Fraser, Wesley C; Milisavljevic, Dan; Nicholson, Philip D; Burns, Joseph A; Carruba, Valerio; Petit, Jean-Marc; Rousselot, Philippe; Mousis, Oliver; Marsden, Brian G; Jacobson, Robert A Discovery of five irregular moons of Neptune, Nature, 430 (2004), pp. 865-867. Final preprint(pdf)
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| Naiad · Thalassa · Despina · Galatea · Larissa · Proteus Triton Nereid · S/2002 N 1 · S/2002 N 2 · S/2002 N 3 · Psamathe · S/2002 N 4 |
| See also: Neptune Trojans · Rings of Neptune |
