(208996) 2003 AZ84
2003 AZ84 and its possible satellite, imaged by the Hubble Space Telescope on 2 December 2005. | |
| Discovery | |
|---|---|
| Discovered by | C. Trujillo M. E. Brown |
| Discovery site | NEAT–Palomar Obs. |
| Discovery date | 13 January 2003 |
| Designations | |
| 2003 AZ84 | |
| TNO · plutino · distant | |
| Orbital characteristics | |
| Epoch 27 April 2019 (JD 2458600.5) | |
| Uncertainty parameter 3 | |
| Observation arc | 20.96 yr (7,654 days) |
| Earliest precovery date | 19 March 1996 |
| Aphelion | 46.555 AU |
| Perihelion | 32.170 AU |
| 39.362 AU | |
| Eccentricity | 0.183 |
| 246.96 yr (90,202 days) | |
| 232.611° | |
| 0° 0m 14.368s / day | |
| Inclination | 13.596° |
| 252.202° | |
| ≈ 27 March 2107 ±2.2 days | |
| 15.211° | |
| Known satellites | 1 (diameter: 72 km) (unrecovered) |
| Physical characteristics | |
| Dimensions | (940±40) × (766±20) × (490±16) km (derived from the unlikely assumption of hydrostatic equilibrium) |
| 772±12 km (assuming HE) 723 km (for albedo 0.097) | |
| Mass | 210×1018 kg (derived from ) 150×1018 kg (derived from ) |
Mean density | 0.87±0.01 g/cm3 (assuming HE) 0.76 g/cm3 |
| 6.7874±0.0002 h | |
| 0.097±0.009 (assuming HE) 0.097 | |
| 20.3 (opposition) | |
| 3.760±0.058 (V) 3.537±0.053 (R) | |
(208996) 2003 AZ84 (provisional designation 2003 AZ84) is a trans-Neptunian object with a possible moon located in the outer regions of the Solar System. It is approximately 940 kilometers across its longest axis, as it has an elongated shape. It belongs to the plutinos – a group of minor planets named after its largest member Pluto – as it orbits in a 2:3 resonance with Neptune in the Kuiper belt. It is the third-largest known plutino, after Pluto and Orcus. It is also one of the largest unnamed objects in the Solar System. It was discovered on 13 January 2003, by American astronomers Chad Trujillo and Michael Brown during the NEAT survey using the Samuel Oschin telescope at Palomar Observatory.
Though elongated in shape, 2003 AZ84 displays a small lightcurve amplitude due to its rotation axis being oriented nearly pole-on; the variability is mainly caused by albedo features on its surface.
The low density of this and many other mid-sized TNOs implies that they have never compressed into fully solid bodies, let alone differentiated or collapsed into hydrostatic equilibrium, and so are highly unlikely to be dwarf planets.