- Scott Sheppard and the hunt for Neptune Trojans on YouTube (time 1:40 min.)
- 385571 Otrera at AstDyS-2, Asteroids—Dynamic Site
- 385571 Otrera at the JPL Small-Body Database
| Discovery [1][2] | |
|---|---|
| Discovered by | S. S. Sheppard C. Trujillo |
| Discovery site | Las Campanas Obs. |
| Discovery date | 16 October 2004 |
| Designations | |
| (385571) Otrera | |
Named after | Otrera (Greek mythology)[2] |
| 2004 UP10 | |
| Neptune trojan · L4 [3] centaur [1] · distant [2] | |
| Orbital characteristics [1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 4 | |
| Observation arc | 8.97 yr (3,277 days) |
| Aphelion | 30.727 AU |
| Perihelion | 29.327 AU |
| 30.027 AU | |
| Eccentricity | 0.0233 |
| 164.54 yr (60,099 days) | |
| 355.52° | |
| 0° 0m 21.6s / day | |
| Inclination | 1.4334° |
| 34.761° | |
| 3.5334° | |
| Physical characteristics | |
| Dimensions | 74 km (est. at 0.10)[4] 100 km[5] |
| 23.3[5] | |
| 8.8[1] | |
385571 Otrera, provisional designation 2004 UP10, is a Neptune trojan leading Neptune's orbit in the outer Solar System. It was discovered by American astronomers Scott Sheppard and Chad Trujillo at Las Campanas Observatory on 16 October 2004.[2] It measures approximately 100 kilometers in diameter and was the second such body to be discovered after 2001 QR322.[3]
Neptune trojans are resonant trans-Neptunian objects in a 1:1 mean-motion orbital resonance with Neptune. These Trojans have a semi-major axis and an orbital period very similar to Neptune's (30.10 AU; 164.8 years).
Otrera belongs to the L4 group, which leads 60° ahead Neptune's orbit. It orbits the Sun with a semi-major axis of 30.027 AU at a distance of 29.3–30.7 AU once every 164 years and 6 months (60,099 days). Its orbit has an eccentricity of 0.02 and an inclination of 1° with respect to the ecliptic.[1]
The discoverers estimate that the body has a mean-diameter of 100 kilometers based on a magnitude of 23.3.[5] Based on a generic magnitude-to-diameter conversion, it measures approximately 74 kilometers in diameter using an absolute magnitude of 8.8 and an assumed albedo of 0.10.[4]
This minor planet was the first Neptune trojan to be named in November 2015. It was named after Otrera, the first Amazonian queen in Greek mythology.[2] The naming scheme is to name these objects after figures related to the Amazons, which was an all-female warrior tribe that fought in the Trojan War on the side of the Trojans against the Greeks.[6]