79360 Sila–Nunam
| Discovery | |
|---|---|
| Discovered by |
Jane X. Luu, David C. Jewitt, Chadwick A. Trujillo, Jun Chen |
| Discovery date | 3 February 1997 |
| Designations | |
| MPC designation | 79360 Sila–Nunam |
| 1997 CS29 | |
| TNO (cubewano) | |
| Adjectives | Silaupian, Nunaupian |
| Orbital characteristics | |
| Epoch 13 January 2016 (JD 2457400.5) | |
| Uncertainty parameter 3 | |
| Observation arc | 6940 days (19.00 yr) |
| Aphelion | 44.8452 AU (6.70875 Tm) |
| Perihelion | 43.3862 AU (6.49048 Tm) |
| 44.1157 AU (6.59961 Tm) | |
| Eccentricity | 0.016536 |
| 293.02 yr (107026 d) | |
| 331.884° | |
| 0.00336367°/day | |
| Inclination | 2.240951° |
| 304.34152° | |
| 222.597° | |
| Known satellites | 1 at 2,777 ± 19 km (1,725 ± 10 mi) |
| Earth MOID | 42.3938 AU (6.34202 Tm) |
| Jupiter MOID | 37.9599 AU (5.67872 Tm) |
| Physical characteristics | |
| Dimensions | ≈ 250±30 km (Sila) ≈ 235±28 km (Nunam) (335+41 −42 km combined) |
| Mass | 1.084 ± 0.022×1019 kg (combined) |
|
Mean density
|
0.72+0.37 −0.22 g/cm3 |
| 300.24 h (12.510 d) | |
|
Sidereal rotation period
|
12.50995 ± 0.00036 d |
| 0.086+0.026 −0.017 |
|
| Temperature | ~42 K (−384 °F) |
| U−B=0.73 B−V=1.08 V−R=0.66±0.04 B−R=1.74 V−I=1.25±0.03 R−J=1.4 V−J=2.06±0.03 J−H=0.38±0.08 V−H=2.45±0.08 |
|
| 21.54–21.78 (2014–2015) | |
| (combined) 5.5, (individual) 6.2 & 6.3 (diff. = 0.12), 5.2 |
|
79360 Sila–Nunam is a double coldclassical Kuiper belt object (cubewano) with components of almost equal size, orbiting beyond Neptune in the Solar System. The name of the system is the combined names of the two bodies, Sila and Nunam.
Sila–Nunam was discovered on 3 February 1997 by Jane X. Luu, David C. Jewitt, Chad Trujillo, and Jun Chen at the Mauna Kea Observatory, Hawaii, and given the provisional designation 1997 CS29. It was resolved as a binary system in Hubble observations of 22 October 2002 by Denise C. Stephens and Keith S. Noll and announced, under the designation S/2005 (79360) 1, on 5 October 2005.
The two components are named after Inuit deities. Sila "spirit" is the Inuit god of the sky, weather, and life force. Nunam "earth" is the Earth goddess, in some traditions Sila's wife. Nunam created the land animals and, in some traditions, the Inuit people (in other traditions Sila created the first people out of wet sand). Sila breathed life into the Inuit.
Sila–Nunam is a dynamically cold classical system (cubewano). It orbits very close to 4:7 mean-motion resonance with Neptune.
In 2010, thermal flux from Sila–Nunam in the far-infrared was measured by the Herschel Space Telescope. As a result, its size, while it was assumed to be a single body, was estimated to lie within the range 250 to 420 km (155 to 260 mi). Now that it is known to be a binary system, one body 95% the size of the other, the diameters are estimated to be 243 and 230 kilometres (151 and 143 mi).
...
Wikipedia