(119979) 2002 WC19
Trans-Neptunian object
From Wikipedia, the free encyclopedia
(119979) 2002 WC19 (provisional designation 2002 WC19) is a twotino, that is, a trans-Neptunian object in a 1:2 orbital resonance with Neptune. It was discovered on November 16, 2002, at the Palomar Observatory. Its estimated diameter predicts a density comparable to that of Pluto, which would be unusual as it is much smaller than the expected size at which a Kuiper belt object would normally becomes solid. However, the error bar for the density is 50%, consistent with the density of water ice to within one sigma.
2002 WC19 and its satellite imaged by the Hubble Space Telescope in 2006 | |
| Discovery | |
|---|---|
| Discovered by | Palomar Observatory |
| Discovery date | 16 November 2002 |
| Designations | |
| (119979) 2002 WC19 | |
| Twotino[1][2] binary | |
| Orbital characteristics[3] | |
| Epoch 13 January 2016 (JD 2457400.5) | |
| Uncertainty parameter 3 | |
| Observation arc | 3978 days (10.89 yr) |
| Aphelion | 60.732 AU (9.0854 Tm) |
| Perihelion | 35.289 AU (5.2792 Tm) |
| 48.010 AU (7.1822 Tm) | |
| Eccentricity | 0.26498 |
| 332.67 yr (121,507 d) | |
| 316.02° | |
| 0° 0m 10.666s / day | |
| Inclination | 9.1746° |
| 109.7547° | |
| â 5 November 2056[4] ±3 days | |
| 44.356° | |
| Known satellites | 1 (81 km)[5] |
| Earth MOID | 34.3056 AU (5.13204 Tm) |
| Jupiter MOID | 29.9229 AU (4.47640 Tm) |
| Physical characteristics | |
| Dimensions | 338±44 km[5] |
| Mass | (8.13±1.0)Ã1019 kg (prograde) or (7.263±0.87)Ã1019 kg (retrograde) [6] |
Mean density | 1.97±1.00 g/cm3 for the average of prograde and retrograde masses[5] (2.08±1.06 g/cm3 if prograde, 1.86±0.94 g/cm3 if retrograde) |
| 0.05[5] | |
| 4.66[3] | |
Knowing how many twotinos there are may reveal whether Neptune took roughly 1 million or 10 million years to migrate about 7 AU from its birth location.[7]
Satellite
| Discovery | |
|---|---|
| Discovered by | K. S. Noll, W. M. Grundy, S. D. Kern, H. F. Levison, D. C. Stephens |
| Discovery site | Hubble Space Telescope |
| Discovery date | 5 November 2006 |
| Orbital characteristics[5] | |
| 4092±94 km | |
| Eccentricity | 0.21±0.05 |
| 8.403±0.001 d | |
| Inclination | 24.0°±0.7° |
| Satellite of | (119979) 2002 WC19 |
| Physical characteristics | |
| 81 km (assuming similar albedo)[5] | |
| primary + 2.5 | |
On February 27, 2007, a natural satellite was reported to be orbiting 2002 WC19. It is estimated to be 4092±94 km from the primary, with an orbital period of 8.403±0.001 days, an eccentricity of 0.21±0.05 and an inclination of 24.0°±0.7°. Assuming similar albedos, it is a quarter the diameter of its primary, or around 81 kilometres (50 mi) in diameter.[5]
Orbit of 2002 WC19 compared to Pluto and Neptune
1:2 libration over 20,000 years â Neptune is held stationary (dot at 5 o'clock); orbit of Uranus in blue
