Inuit group
Kiviuq · Ijiraq · Paaliaq · Siarnaq · Tarqeq
The Inuit group is a dynamical grouping of the prograde irregular satellites of Saturn which follow similar orbits. Their semi-major axes range between 11 and 19 Gm, their inclinations between 43° and 51°, and their eccentricities between 0.08 and 0.39. They take an average of 2 years to orbit Saturn.
The International Astronomical Union (IAU) uses names taken from Inuit mythology for these moons.
The group appeared quite homogeneous in early observations, the satellites displaying light-red colour (colour indices B−V = 0.79 and V−R = 0.51, similar to that of the Gallic group)[1] and similar infrared spectra.[2] Recent observations, however, revealed that Ijiraq is distinctly redder than Paaliaq, Siarnaq and Kiviuq. In addition, unlike the other three, Ijiraq's spectrum does not display weak absorption near 0.7 μm. This feature is attributed to a possible water hydration.[3]
The spectral homogeneity (with the exception of Ijiraq) is consistent with a common origin in the break-up of a single object but the dispersion of the orbital parameters requires further explanation. Secular resonances among the members could provide the explanation of the post-collisional dispersion.
Subgroups
[edit]The Inuit group can be separated into three subgroups that are each associated with the moons Kiviuq, Siarnaq, and Paaliaq. The Kiviuq subgroup is composed of 20 members and have semi-major axes between 11 million km and 13 million km, inclinations between 44° and 51°, and eccentricities between 0.25 and 0.39. The Siarnaq subgroup is composed of 15 members and have semi-major axes between 17 million km and 19 million km, inclinations between 43° and 49°, and eccentricities between 0.08 and 0.31. Paaliaq is by itself and orbits at a distance in between the two other subgroups.
Names
[edit]The thirty six known members of the Inuit group are (sorted by date announcement):
| Name | Diameter (Km) | Semi-Major Axis (Km) | Period (days)[4] | Subgroup |
|---|---|---|---|---|
| Paaliaq | 30 | 14997900 | 686.94 | Paaliaq |
| Siarnaq | 39.3 | 17881100 | 895.58 | Siarnaq |
| Kiviuq | 19 | 11307500 | 449.13 | Kiviuq |
| Ijiraq | 15 | 11344600 | 451.43 | Kiviuq |
| Tarqeq | 7 | 17751000 | 884.99 | Siarnaq |
| S/2004 S 31 | 5 | 17497200 | 866.09 | Siarnaq |
| S/2019 S 1 | 5 | 11245400 | 445.51 | Kiviuq |
| S/2020 S 1 | 4 | 11338600 | 451.10 | Kiviuq |
| S/2020 S 3 | 3 | 18057200 | 908.19 | Siarnaq |
| S/2020 S 5 | 3 | 18391400 | 933.89 | Siarnaq |
| S/2019 S 6 | 4 | 18205500 | 919.71 | Siarnaq |
| S/2005 S 4 | 5 | 11324500 | 450.22 | Kiviuq |
| S/2019 S 14 | 4 | 17853200 | 893.14 | Siarnaq |
| S/2004 S 54 | 4 | 11277500 | 447.14 | Kiviuq |
| S/2004 S 55 | 3 | 11294700 | 448.16 | Kiviuq |
| S/2004 S 58 | 5 | 18254500 | 920.80 | Siarnaq |
| S/2005 S 6 | 4 | 18107300 | 909.58 | Siarnaq |
| S/2006 S 23 | 3 | 18269700 | 921.86 | Siarnaq |
| S/2007 S 10 | 4 | 11364900 | 452.36 | Kiviuq |
| S/2019 S 22 | 3 | 11305100 | 448.48 | Kiviuq |
| S/2019 S 23 | 3 | 11310200 | 449.08 | Kiviuq |
| S/2019 S 24 | 4 | 11360500 | 452.07 | Kiviuq |
| S/2019 S 25 | 4 | 11329400 | 450.22 | Kiviuq |
| S/2019 S 26 | 3 | 11390900 | 453.89 | Kiviuq |
| S/2019 S 32 | 5 | 17960500 | 898.71 | Siarnaq |
| S/2020 S 11 | 3 | 11295600 | 448.21 | Kiviuq |
| S/2020 S 12 | 3 | 11314500 | 449.33 | Kiviuq |
| S/2020 S 13 | 3 | 11415600 | 455.39 | Kiviuq |
| S/2020 S 19 | 3 | 17726700 | 881.04 | Siarnaq |
| S/2023 S 1 | 3 | 11205400 | 442.86 | Kiviuq |
| S/2023 S 2 | 3 | 11309900 | 449.05 | Kiviuq |
| S/2023 S 3 | 3 | 17646400 | 875.00 | Siarnaq |
| S/2023 S 6 | 3 | 11953100 | 487.91 | Kiviuq |
| S/2023 S 7 | 4 | 12133700 | 499.01 | Kiviuq |
| S/2023 S 19 | 3 | 17590300 | 870.92 | Siarnaq |
| S/2023 S 22 | 4 | 18577500 | 945.37 | Siarnaq |
See also
[edit]References
[edit]- ^ Grav, Tommy; Holman, Matthew J.; Gladman, Brett; Aksnes, Kaare (November 2003). "Photometric Survey of the Irregular Satellites". Icarus. 166 (1): 33–45. arXiv:astro-ph/0301016. Bibcode:2003Icar..166...33G. doi:10.1016/j.icarus.2003.07.005.
- ^ Grav, Tommy; Holman, Matthew J. (2004-04-20). "Near-Infrared Photometry of 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. ISSN 0004-637X.
- ^ Grav, Tommy; Bauer, James (2007-11-01). "A deeper look at the colors of the Saturnian irregular satellites". Icarus. 191 (1): 267–285. arXiv:astro-ph/0611590. Bibcode:2007Icar..191..267G. doi:10.1016/j.icarus.2007.04.020.
- ^ "Planetary Satellite Mean Elements". Jet Propulsion Laboratory. California Institute of Technology. 25 January 2024.
External links
[edit]Mean orbital parameters: from JPL
