Sinope (moon)

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Categories: Jupiter's moons | Irregular satellites

**Sinope**
Discovery
Discovered by	S. B. Nicholson
Discovery date	July 21, 1914
Orbital characteristics
Periapsis	18,237,600 km
Apoapsis	30,191,200 km
Mean orbit radius	23,540,000 km^[2]
Eccentricity	0.25^[2]
Orbital period	724.1 d (1.95 a)^[2]
Average orbital speed	2.252 km/s
Inclination	128.11° (to the ecliptic) 153.12° (to Jupiter's equator)^[2]
Satellite of	Jupiter
Physical characteristics
Mean radius	~19 km
Volume	~28,700 km³
Mass	7.5×10¹⁶ kg
Mean density	2.6 g/cm³ (assumed)
Equatorial surface gravity	0.014 m/s² (0.001 g)
Escape velocity	~0.023 km/s
Albedo	0.04 (assumed)
Temperature	~124 K

Sinope (sə-noe'-pee, IPA: /sɨˈnoʊpi/; Greek Σινώπη) is a retrograde irregular satellite of Jupiter discovered by Seth Barnes Nicholson at Lick Observatory in 1914,^[3] and is named after Sinope of Greek mythology.

Sinope did not receive its present name until 1975^[4]^[5]; before then, it was simply known as Jupiter IX. It was sometimes called "Hades"^[6] between 1955 and 1975.

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.

1 Orbit
2 Physical characteristics
3 See also
4 References
5 External links

Orbit

Image:TheIrregulars JUPITER Pasiphae CORE.svg

Pasiphae group.

Sinope orbits Jupiter on a high eccentricity and high inclination retrograde orbit. The orbital elements are as of January 2000.^[2] They are continuously changing due to Solar and planetary perturbations. It is often believed to belong to the Pasiphaë group.^[7] 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.^[8] 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 resonant behaviour in time scales of 10⁷ years.^[9]

Physical characteristics

Sinope has an estimated diameter of 38 km (assuming an albedo of 0.04)^[7] The satellite is red (colour indices B-V=0.84, R-V=0.46).^[8] unlike Pasiphae which is grey.

Its infrared spectrum is similar to D-type asteroids also different from Pasiphae.^[10] These dissimilarities of the physical parameters suggest a different origin from the core members of the group.

References

^ [1]
^ ^a ^b ^c ^d ^e Jacobson, R. A. (2000). "The Orbits of the Outer Jovian Satellites". Astronomical Journal 120: pp. 2679-2686. doi:10.1086/316817.
^ Nicholson, S. B. (1914). "Discovery of the Ninth Satellite of Jupiter". Publications of the Astronomical Society of the Pacific 26: pp. 197-198.
^ Nicholson, S. B. (April 1939). "The Satellites of Jupiter". Publications of the Astronomical Society of the Pacific 51 (300): pp. 85–94. (in which he declines to name the recently discovered satellites (pp. 93–94))
^ IAUC 2846: Satellites of Jupiter 1974 October 7 (naming the moon)
^ Payne-Gaposchkin, Cecilia; Katherine Haramundanis (1970). Introduction to Astronomy. Englewood Cliffs, N.J.: Prentice-Hall. ISBN 0-134-78107-4.
^ ^a ^b Sheppard, S. S.; and Jewitt, D. C.; An Abundant Population of Small Irregular Satellites Around Jupiter, Nature, Vol. 423 (May 2003), pp. 261-263
^ ^a ^b Grav, T.; Holman, M. J.; Gladman, B. J.; and Aksnes, K.; Photometric Survey of the Irregular Satellites, Icarus, Vol. 166 (2003), pp. 33-45
^ Nesvorný, D.; Beaugé, C.; and Dones, L. (2004). "Collisional Origin of Families of Irregular Satellites". The Astronomical Journal 127: pp. 1768–1783.
^ Grav, T.; and Holman, M. J. (2004). "Near-Infrared Photometry of the Irregular Satellites of Jupiter and Saturn". The Astrophysical Journal 605: pp. L141–L144.

External links

v • d • e

Moons of Jupiter

Listed in increasing distance from Jupiter. Temporary names in italics.

Inner moons

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

core	Ananke · Praxidike · Harpalyke · Iocaste · Euanthe · Thyone
peripheral	Euporie · S/2003 J 3 · S/2003 J 18 · Thelxinoe · Helike · Orthosie · S/2003 J 16 · Hermippe · Mneme · S/2003 J 15

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