Sinope is a retrograde

irregular satellite In astronomy, an irregular moon, irregular satellite, or irregular natural satellite is a natural satellite following an orbit that is irregular in some of the following ways: Distant; inclined; highly elliptical; retrograde. They have often be ...

Jupiter Jupiter is the fifth planet from the Sun and the List of Solar System objects by size, largest in the Solar System. It is a gas giant with a Jupiter mass, mass more than 2.5 times that of all the other planets in the Solar System combined a ...

discovered by Seth Barnes Nicholson at

Lick Observatory The Lick Observatory is an astronomical observatory owned and operated by the University of California. It is on the summit of Mount Hamilton (California), Mount Hamilton, in the Diablo Range just east of San Jose, California, United States. The ...

in 1914, and is named after Sinope of

Greek mythology Greek mythology is the body of myths originally told by the Ancient Greece, ancient Greeks, and a genre of ancient Greek folklore, today absorbed alongside Roman mythology into the broader designation of classical mythology. These stories conc ...

. Sinope did not receive its present name until 1975; (in which he declines to name the recently discovered satellites (pp. 93–94))IAUC 2846: ''Satellites of Jupiter''
1974 October (naming the moon) before then, it was simply known as . It was sometimes called "

Hades Hades (; , , later ), in the ancient Greek religion and Greek mythology, mythology, is the god of the dead and the king of the Greek underworld, underworld, with which his name became synonymous. Hades was the eldest son of Cronus and Rhea ...

" between 1955 and 1975.

Orbit

Sinope orbits Jupiter on a high-eccentricity and high-inclination retrograde orbit. Its orbit is continuously changing due to solar and planetary perturbations. Sinope is believed to belong to the Pasiphae group of retrograde irregular moons. Sheppard, S. S.; and Jewitt, D. C.
''An Abundant Population of Small Irregular Satellites Around Jupiter''
Nature, Vol. 423 (May 2003), pp. 261-263 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. Grav, T.; Holman, M. J.; Gladman, B. J.; and Aksnes, K.
''Photometric Survey of the Irregular Satellites''
Icarus, Vol. 166 (2003), pp. 33-45 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.

Physical characteristics

From measurements of its thermal emission, Sinope has an estimated diameter of . Sinope is pale red in color ( colour indices V=18.63 B−V=0.84, R−V=0.46), and it falls under the light red color-class, comparable to

P-type asteroid P-type (primitive-type) asteroids have low albedo and a featureless reddish spectrum. It has been suggested that they have a composition of organic-rich silicates, carbon and anhydrous silicates, possibly with water ice in their interior. P-type ...

s and

D-type asteroid D-type asteroids have a very low albedo and a featureless reddish spectrum. It has been suggested that they have a composition of organic-rich silicates, carbon and anhydrous silicates, possibly with water ice in their interiors. D-type asteroids ...

s. This sets it apart from Pasiphae, which is closer to

C-type asteroid C-type (carbonaceous ) asteroids are the most common variety, forming around 75% of known asteroids. They are volatile-rich and distinguished by a very low albedo because their composition includes a large amount of carbon, in addition to rocks ...

s. Sinope's

infrared Infrared (IR; sometimes called infrared light) is electromagnetic radiation (EMR) with wavelengths longer than that of visible light but shorter than microwaves. The infrared spectral band begins with the waves that are just longer than those ...

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is similar to those of

s but different from that of Pasiphae. These dissimilarities of the physical parameters suggest a different origin from the core members of the group.

References

External links

Sinope Profile
b
NASA's Solar System Exploration
(by Scott S. Sheppard) * Ephemeri
IAU-MPC NSES
{{DEFAULTSORT:Sinope (Moon) Moons of Jupiter Irregular satellites 19140721 Pasiphae group Moons with a retrograde orbit

Orbit

Physical characteristics

See also

References

External links