Siarnaq (moon)

Siarnaq (moon)

Irregular satellite
ref_discovery=Discovery Circumstances [ (JPL)] ]

name=Siarnaq - Saturn XXIX
discoverer=Brett J. Gladman "et al."
discovery_date=in 2000
epoch=2000 Feb. 26.00
ref_orb_elems=Mean orbital parameters [ from JPL] ]
period=895.55 d (2.45 yr)
diameter=40 km [ Scott Sheppard pages] ]
albedo=0.04 "assumed"
color="light red" B-V=0.87 R-V=0.48Grav, T.; and Bauer, J.; [ "A deeper look at the colors of Saturnian irregular satellites"] ]

Siarnaq (pronEng|ˈsiːɑrnɑːk "SEE-ar-naak)," or Saturn XXIX, is a prograde irregular satellite of Saturn. It was discovered by Brett J. Gladman, et al. in 2000 [ [ IAUC 7513: "S/2000 S 3 and S/2000 S 4"] 2000 October 25 (discovery)] , [ [ MPEC 2000-Y14: "S/2000 S 3, S/2000 S 4, S/2000 S 5, S/2000 S 6, S/2000 S 10"] 2000 December 19 (discovery and ephemeris)] and given the temporary designation S/2000 S 3.Named in August 2003 after the giant Siarnaq [ [ IAUC 8177: "Satellites of Jupiter, Saturn, Uranus"] 2003 August 8 (naming the moon)] (also known as Sedna) in Inuit mythology, it is the largest member of the Inuit group of irregular satellites.

Siarnaq is thought to be about 40 kilometres in diameter and orbits Saturn at an average distance of 17.5 Gm in 895 days.

The diagram illustrates its orbit in relation to other prograde irregular satellites of Saturn. The eccentricity of the orbits is represented by the yellow segments extending from the pericentre to the apocentre.

Siarnaq displays light-red colours and the infrared spectrum very similar to Paaliaq and Kiviuq, supporting the thesis of a possible common origin in the break-up of a larger bodyGladman, B. J.; Nicholson, P. D.; Burns, J. A.; Kavelaars, J. J.; Marsden, B. G.; Holman, M. J.; Grav, T.; Hergenrother, C. W.; Petit, J.-M.; Jacobson, R. A.; and Gray, W. J.; [ "Discovery of 12 satellites of Saturn exhibiting orbital clustering"] , Nature, 412 (2001 July 12), pp. 163–166] Grav, T.; Holman, M. J.; Gladman, B. J.; Aksnes, K.; [ "Photometric survey of the irregular satellites"] , Icarus, 166 (2003), pp. 33-45] .

Siarnaq has been found to be in a secular resonance with Saturn, involving the precession of its periapsis and that of the planet.
Ćuk, M.; Burns, J. A.; [ "On the Secular Behavior of Irregular Satellites"] , The Astronomical Journal, 128 (2004), pp. 2518-2541] 1

The studies of these resonances are key to understand the capture mechanism for the irregular satellites and, assuming a common origin of a given dynamical group in the break-up of a single body, to explain today’s dispersion of the orbital elements.

1The ecliptic longitudes of the periapsis of the satellite and the planet are locked.


*Ephemeris [ IAU-MPC NSES]

External links

* [ David Jewitt pages]
* [ Scott Sheppard pages]

Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Titan (moon) — Titan Titan in 2005 by Cassini spacecraft Discovery Discovered by Christiaan Huygens …   Wikipedia

  • Mimas (moon) — Mimas Mimas with its large crater Herschel (Cassini, 2010 02 13) Discovery Discovered by William Herschel …   Wikipedia

  • Daphnis (moon) — Daphnis Daphnis in cropped Cassini probe image (July 06, 2010). Discovery Discovered by Cassini Imaging Science Team …   Wikipedia

  • Dione (moon) — Not to be confused with the asteroid called 106 Dione. For other uses, see Dione. Dione Cassini view of Dione s leading hemisphere. The large craters on or near the terminator are (from bottom to top) Evander, Erulus, Lagus and Sagaris. The… …   Wikipedia

  • Chiron (hypothetical moon) — This article is about the hypothetical moon of Saturn. For other uses, see Chiron (disambiguation). Chiron (Greek: Χοίρων) is the name given to a supposed moon of Saturn sighted by Hermann Goldschmidt in 1861. It has since been determined that no …   Wikipedia

  • Helene (moon) — Helene Cassini image of Helene against the backdrop of Saturn s clouds (March 3, 2010) Discovery Discovered by Laques and Lecacheux …   Wikipedia

  • Methone (moon) — Methone Methone as seen by Cassini taken in September, 2010 Discovery Discovered by Cassini Imaging Science Team Discovery date …   Wikipedia

  • Kiviuq (moon) — Irregular satellite ref discovery=Discovery Circumstances [ discovery (JPL)] ] name=Kiviuq Saturn XXIV discoverer=B. J. Gladman et al. discovery date=in 2000 epoch=2000 Feb. 26.00 ref orb elems=Mean orbital parameters… …   Wikipedia

  • Ijiraq (moon) — Irregular satellite ref discovery=Discovery Circumstances [ discovery (JPL)] ] name=Ijiraq Saturn XXII discoverer=J. J. Kavelaars B. J. Gladman discovery date=in 2000 epoch=2000 Feb. 26.00 ref orb elems=Mean orbital… …   Wikipedia

  • Mundilfari (moon) — Mundilfari (  /ˈmʊn …   Wikipedia