90568 Goibniu
Goibniu imaged by the Hubble Space Telescope on 17 March 2010 | |
| Discovery | |
|---|---|
| Discovered by | NEAT (obs. code 644) |
| Discovery site | Palomar Obs. |
| Discovery date | 13 April 2004 |
| Designations | |
| (90568) Goibniu | |
| Pronunciation | /ˈɡɔɪvnjuː/ |
Named after | Goibniu |
| 2004 GV9 | |
| Orbital characteristics (barycentric) | |
| Epoch 5 May 2025 (JD 2460800.5) | |
| Uncertainty parameter 0 or 1 | |
| Observation arc | 70+ yr |
| Earliest precovery date | 21 December 1954 |
| Aphelion | 45.160 AU |
| Perihelion | 38.730 AU |
| 41.945 AU | |
| Eccentricity | 0.0766 |
| 271.48 yr (99,158 d) | |
| 48.258° | |
| 0° 0m 13.07s / day | |
| Inclination | 21.983° |
| 250.605° | |
| 292.116° | |
| Known satellites | 0 |
| Physical characteristics | |
| 680±34 km | |
Mean density | >0.37 g/cm3 (lower limit) |
| 5.86±0.03 | |
| 0.077+0.0084 −0.0077 | |
| 19.9 | |
| |
90568 Goibniu (provisional designation 2004 GV9) is a large trans-Neptunian object that was discovered in 2004 by the Near-Earth Asteroid Tracking survey at Palomar Observatory. It is classified as a classical Kuiper belt object of the dynamically "hot" population, which follow highly inclined or eccentric orbits around the Sun.
Goibniu is 680 ± 34 km (423 ± 21 mi) in diameter, according to measurements of its infrared thermal emission by the Herschel and Spitzer space telescopes. It shows small variations in brightness (0.16 magnitudes) over its 5.86-hour rotation period. Some astronomers have suggested that Goibniu is large enough that it could be a dwarf planet. However, the shape of Goibniu is unknown–it could either be a spheroid with small albedo spots or an ellipsoid whose rotation axis is pointed towards Earth. Furthermore, its low albedo suggests it has never been resurfaced and thus is unlikely to have the planetary geology thought to be typical of dwarf planets.