Sinope

Sinope
Name	Sinope
Designation	Jupiter IX
Discoverer	S. B. Nicholson
Discovery date	1914
Category	Irregular satellite
Mean radius km	19
Semi major axis gm	23.540
Eccentricity	0.287
Inclination deg	158.1
Orbital period days	-758.1
Albedo	0.04

Sinope is a natural satellite of Jupiter classified among the planet's outer, irregular moons. It occupies a retrograde, highly inclined and eccentric orbit, making it part of the population studied alongside members of the Pasiphae group and compared with objects like Himalia and Ananke. Its discovery in the early 20th century and subsequent identification with mythological nomenclature linked planetary astronomy with classical traditions used by institutions such as the International Astronomical Union.

Etymology and Name

The name derives from the mythological figure Sinope of Greek mythology, a daughter associated with figures from the cycles surrounding Apollo and Zeus. The designation as Jupiter IX follows the numerical convention established after the sequential discoveries of Jupiter's satellites beginning with Io, Europa, Ganymede, and Callisto. The naming decisions reflect practices codified by the International Astronomical Union in the 20th century and echo earlier naming patterns set by astronomers linked to observatories such as the Mount Wilson Observatory and institutions like the Harvard College Observatory.

Mythology

In Greek mythology, Sinope appears in tales involving patrons such as Apollo and encounters with Zeus, with narratives preserved in works attributed to ancient authors like Diodorus Siculus and commentators within the tradition of Hellenistic literature. Variants of her story intersect with myths of colonization and eponymous founders, connecting to locales such as the city of Sinop on the southern shore of the Black Sea, historically linked to colonies from Miletus and to sources cited by geographers like Strabo. Mythic motifs around Sinope have been discussed in scholarship from the fields represented by institutions including the British Museum and the Louvre.

Astronomy (Moon of Jupiter)

As an outer irregular satellite, Sinope is categorized with retrograde moons such as Pasiphae and Sinope's cohort, which are studied in the context of capture hypotheses involving interactions with the solar nebula, perturbations from Saturn and resonant mechanisms explored in research from observatories like Palomar Observatory and missions such as Voyager and Galileo spacecraft. Photometric and spectroscopic surveys conducted by teams at facilities including Keck Observatory and Very Large Telescope aim to determine compositional affinities with populations like the C-type asteroid and D-type asteroid classes cataloged by projects such as the Sloan Digital Sky Survey.

Physical Characteristics and Orbit

Sinope's estimated mean radius (~19 km) and low geometric albedo (~0.04) align it with dark, carbonaceous bodies similar to D-type asteroid specimens found in the outer Main Belt. Its orbit, with semi-major axis around 23.5 million km, eccentricity ~0.29 and inclination ~158°, yields a retrograde orbital period of about −758 days (negative sign indicating retrograde motion in some ephemerides). Dynamical studies by researchers affiliated with institutions such as NASA's Jet Propulsion Laboratory and university groups at University of Arizona model perturbations from Jupiter and long-term stability influenced by secular resonances with Saturn and interactions cataloged in datasets maintained by the Minor Planet Center.

Discovery and Observation

Sinope was first reported in 1914 by S. B. Nicholson at the Lick Observatory using photographic techniques then becoming standard at facilities including Yerkes Observatory and Mount Wilson Observatory. It was temporarily lost and later recovered through astrometric efforts coordinated with catalogs like the Astrophysical Journal publications and compiled in ephemerides by the Jet Propulsion Laboratory and the Minor Planet Center. Observational campaigns using large aperture telescopes such as Keck Observatory and survey instruments tied to projects like the Pan-STARRS program have refined its orbit and photometric properties, while mission planners for probes such as Galileo spacecraft and ground-based teams continue to monitor populations of irregular satellites.

Cultural References and Legacy

Sinope's mythic name and status among Jupiter's retinue have led to appearances in cultural materials referencing Greek mythology and astronomical nomenclature promulgated by bodies like the International Astronomical Union; it appears in catalogues, planetarium programs at institutions such as the Griffith Observatory and in educational materials produced by organizations including the Smithsonian Institution and NASA's public outreach offices. The link between the mythological character, the Black Sea city of Sinop, and scholarly collections at museums such as the British Museum has also sustained Sinope's presence in works on classical reception and maritime history curated by universities like University of Oxford and Harvard University.

Category:Jupiter moons