Sinope (moon)
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| Discovery | |
|---|---|
| Discovered by: | S. B. Nicholson |
| Discovery date: | July 21, 1914 |
| Orbital characteristics | |
| Periapsis: | 18,237,600 km (0.122 AU) |
| Apoapsis: | 30,191,200 km (0.202 AU) |
| Mean radius of orbit: | 24,214,390 km (0.16186 AU) |
| Orbital circumference: | 149,800,000 km (1.001 AU) |
| Eccentricity: | 0.2468 |
| Orbital period: | 769.779665 d (2.078 a) |
| Avg. orbital speed: | 2.252 km/s |
| Max. orbital speed: | 2.943 km/s |
| Min. orbital speed: | 1.778 km/s |
| Inclination: | 155.25° (to the ecliptic) 153.12° (to Jupiter's equator) |
| Satellite of: | Jupiter |
| Physical characteristics | |
| Mean radius: | 19 km |
| Volume: | ~28,700 km3 |
| Mass: | 7.5×1016 kg |
| Mean density: | 2.6 g/cm3 |
| Equatorial surface gravity: | 0.014 m/s2 (0.001 g) |
| Escape velocity: | ~0.023 km/s |
| Albedo: | 0.04 |
| Temperature: | ~124 K |
Sinope (sə-noe'-pee, IPA: [səˈnoʊpi]; Greek Σινώπη) is a retrograde irregular satellite of Jupiter discovered by Seth Barnes Nicholson at Lick Observatory in 1914, and is named after Sinope of Greek mythology.[1]
Sinope did not receive its present name until 1975; before then, it was simply known as Jupiter IX. It was sometimes called "Hades".
Sinope was the outermost known moon of Jupiter until the discovery of Megaclite in 2000. The most distant moon of Jupiter now known is S/2003 J2.
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[edit] Orbit
Sinope orbits Jupiter on a high eccentricity and high inclination retrograde orbit. It is often believed to belong to the Pasiphaë group.[2] However, given its mean inclination and different colour, Sinope could be also an independent object, captured independently, unrelated to the collision and break-up at the origin of the group.[3]
The diagram illustrates Sinope's orbital elements in relation to other satellites of the group.
Sinope is also known to be in a secular resonance with Jupiter, similar to Pasiphae. However, Sinope can drop out of this resonance and has periods of both resonant and non resonance behavior in timescales of 107 years.[4]
[edit] Physical characteristics
Sinope has an estimated diameter of 38 km (assuming albedo of 0.04)[2] The satellite is red (colour indices B-V=0.84, R-V=0.46).[3] unlike Pasiphae which is grey.
Its infrared spectrum is similar to D-type asteroids also different from Pasiphae.[5] These dissimilarities of the physical parameters suggest a different origin from the core members of the group.
[edit] See also
[edit] External links
[edit] References
- ^ Seth B. Nicholson, Discovery of the ninth satellite of Jupiter, PASP 26 (1914) 197–198] [1]
- ^ a b Scott S. Sheppard, David C. Jewitt An abundant population of small irregular satellites around Jupiter, Nature, 423 (May 2003), pp.261-263 Full text(pdf).
- ^ a b Grav, Tommy; Holman, Matthew J.; Gladman, Brett J.; Aksnes, Kaare Photometric survey of the irregular satellites,Icarus, 166,(2003), pp. 33-45. Preprint
- ^ David Nesvorný, Jose L. A. Alvarellos, Luke Dones, and Harold F. Levison Orbital and Collisional Evolution of the Irregular Satellites, The Astronomical Journal,126 (2003), pages 398–429. (pdf)
- ^ 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
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Listed in increasing distance from Jupiter. Italics indicate ungrouped moons.
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| Amalthea group | Metis · Adrastea · Amalthea · Thebe |
| Galilean moons | Io · Europa · Ganymede · Callisto |
| Themisto | |
| Himalia group | Leda · Himalia · Lysithea · Elara · S/2000 J 11 |
| Carpo · S/2003 J 12 | |
| Ananke group | Ananke · Praxidike · Harpalyke · Iocaste · Euanthe · Thyone (core) Euporie · S/2003 J 3 · S/2003 J 18 · Thelxinoe · Helike · Orthosie · S/2003 J 16 · Hermippe · Mneme · S/2003 J 15 (peripheral) |
| Carme group | S/2003 J 17 · S/2003 J 10 · Pasithee · Chaldene · Arche · Isonoe · Erinome · Kale · Aitne · Taygete · S/2003 J 9 · Carme · S/2003 J 5 · S/2003 J 19 · Kalyke · Eukelade · Kallichore |
| Pasiphaë group | Eurydome · S/2003 J 23 · Hegemone · Pasiphaë · Sponde · Cyllene · Megaclite · S/2003 J 4 · Callirrhoe · Sinope · Autonoe · Aoede · Kore |
| S/2003 J 2 | |
