(612243) 2001 QR322
| Discovery | |
|---|---|
| Discovered by | M. W. Buie (DES) | 
| Discovery site | Cerro Tololo Obs. | 
| Discovery date | 21 August 2001 | 
| Designations | |
| (612243) 2001 QR322 | |
| 2001 QR322 | |
| Neptune trojan · L4 TNO · distant | |
| Orbital characteristics | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 3 | |
| Observation arc | 12.26 yr (4,479 days) | 
| Aphelion | 30.968 AU | 
| Perihelion | 29.262 AU | 
| 30.115 AU | |
| Eccentricity | 0.0283 | 
| 165.27 yr (60,363 days) | |
| 86.551° | |
| 0° 0m 21.6s / day | |
| Inclination | 1.3250° | 
| 151.75° | |
| 151.11° | |
| Physical characteristics | |
| 132 km | |
| 0.058 | |
| 22.5 | |
| 8.12 | |
(612243) 2001 QR322, prov. designation: 2001 QR322, is a minor planet and the first Neptune trojan discovered, by American astronomer Marc Buie of the Deep Ecliptic Survey at Cerro Tololo Observatory in Chile on 21 August 2001. It orbits ahead of Neptune at its L4 Lagrangian point and measures approximately 132 kilometers (82 miles) in diameter.
Other Neptune trojans have been discovered since. A study by American astronomers Scott Sheppard and Chad Trujillo from the Carnegie Institution suggests that Neptune could possibly have twenty times more trojans than Jupiter.