Sinope (moon)
Sinope is a non-spherical moon of Jupiter. It was found by Seth Barnes Nicholson at Lick Observatory in 1914,[4] and is named after Sinope of Greek mythology.
 | |
| 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[1] |
| Eccentricity | 0.25[1] |
| 724.1 d (1.95 a)[1] | |
Average orbital speed | 2.252 km/s |
| Inclination | 128.11° (to the ecliptic) 153.12° (to Jupiter's equator)[1] |
| Satellite of | Jupiter |
| Physical characteristics | |
Mean radius | ~19 km[2][3] |
| ~4500 km2 | |
| Volume | ~28,700 km3 |
| Mass | 7.5×1016 kg |
Mean density | 2.6 g/cm3 (assumed)[2] |
| 0.014 m/s2 (0.001 g) | |
| ~0.023 km/s | |
| Albedo | 0.04 (assumed)[2][3] |
| Temperature | ~124 K |
Sinope did not get its present name until 1975;[5][6] before then, it was simply known as Jupiter IX. It was sometimes called "Hades"[7] between 1955 and 1975.
Sinope was the farthest known moon of Jupiter until the discovery of Megaclite in 2000. The farthest moon of Jupiter now known is S/2003 J 2.
Orbit change
Sinope orbits Jupiter on a high eccentricity and high inclination retrograde orbit. The orbital elements are as of January 2000.[1] They are changing a lot due to Solar and planetary perturbations. It is often believed to belong to the Pasiphaë group.[3] 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 moons of the group.
Physical characteristics change
Sinope has an estimated diameter of 38 km (assuming an albedo of 0.04)[3] The moon is red[8] unlike Pasiphae which is grey.
Its infrared spectrum is similar to D-type asteroids also different from Pasiphae.[9] These dissimilarities of the physical parameters suggest a different origin from the core members of the group.
References change
- ↑ 1.0 1.1 1.2 1.3 1.4 Jacobson, R. A. (2000). "The Orbits of the Outer Jovian Satellites". Astronomical Journal. 120 (5): 2679–2686. Bibcode:2000AJ....120.2679J. doi:10.1086/316817. S2CID 120372170. Archived from the original on 2019-12-13. Retrieved 2019-04-26.
- ↑ 2.0 2.1 2.2 "Planetary Satellite Physical Parameters". JPL (Solar System Dynamics). 2008-10-24. Retrieved 2008-12-12.
- ↑ 3.0 3.1 3.2 3.3 Sheppard, S. S.; and Jewitt, D. C.; "An Abundant Population of Small Irregular Satellites Around Jupiter", Nature, Vol. 423 (May 2003), pp. 261-263
- ↑ Nicholson, S. B. (1914). "Discovery of the Ninth Satellite of Jupiter". Publications of the Astronomical Society of the Pacific. 26 (155): 197–198. Bibcode:1914PASP...26..197N. doi:10.1086/122336. PMC 1090718. PMID 16586574.
- ↑ Nicholson, S. B. (April 1939). "The Satellites of Jupiter". Publications of the Astronomical Society of the Pacific. 51 (300): 85–94. Bibcode:1939PASP...51...85N. doi:10.1086/125010. S2CID 122937855. (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.
- ↑ 8.0 8.1 Grav, T.; Holman, M. J.; Gladman, B. J.; and Aksnes, K.; "Photometric Survey of the Irregular Satellites", Icarus, Vol. 166 (2003), pp. 33-45
- ↑ Grav, T.; and Holman, M. J. (2004). "Near-Infrared Photometry of the Irregular Satellites of Jupiter and Saturn". The Astrophysical Journal. 605 (2): L141–L144. arXiv:astro-ph/0312571. Bibcode:2004ApJ...605L.141G. doi:10.1086/420881. S2CID 15665146.