(316179) 2010 EN65
Jumping Neptune trojan
From Wikipedia, the free encyclopedia
(316179) 2010 EN65 is a trans-Neptunian object orbiting the Sun. However, with a semi-major axis of 30.8 AU, the object is actually a jumping Neptune trojan, co-orbital with Neptune, as the giant planet has a similar semi-major axis of 30.1 AU. The body is jumping from the Lagrangian point L4 into L5 via L3.[4] As of 2016[update], it is 54 AU from Neptune. By 2070, it will be 69 AU from Neptune.[7]
| Discovery[1][2] | |
|---|---|
| Discovered by | D. L. Rabinowitz S. W. Tourtellotte |
| Discovery site | La Silla Obs. |
| Discovery date | 7 March 2010 |
| Designations | |
| (316179) 2010 EN65 | |
| TNO[3] · Neptune trojan[4] distant[2] | |
| Orbital characteristics[3] | |
| Epoch 23 March 2018 (JD 2458200.5) | |
| Uncertainty parameter 2 | |
| Observation arc | 25.45 yr (9,296 days) |
| Aphelion | 40.367 AU |
| Perihelion | 21.148 AU |
| 30.758 AU | |
| Eccentricity | 0.3124 |
| 170.58 yr (62,306 days) | |
| 48.107° | |
| 0° 0m 20.88s / day | |
| Inclination | 19.209° |
| 234.47° | |
| 225.77° | |
| Physical characteristics | |
| 176 km (est. at 0.08)[5][6] | |
| 7.17[3] | |
Discovery
2010 EN65 was discovered on 7 March 2010, by David L. Rabinowitz and Suzanne W. Tourtellotte using the 1.3-meter Small and Medium Research Telescope System (SMARTS) at Cerro Tololo Observatory in Chile.[1]
Orbit
2010 EN65 follows a rather eccentric orbit (0.31) with a semi-major axis of 30.72 AU and an inclination of 19.3º.[3] Its orbit is well determined with images dating back to 1989.

2010 EN65 · Neptune · Sun
Physical properties
Jumping trojan
2010 EN65 is another co-orbital of Neptune, the second brightest after the quasi-satellite (309239) 2007 RW10. 2010 EN65 is currently transitioning from librating around Lagrangian point L4 to librating around L5.[4] This unusual trojan-like behavior is termed "jumping trojan".[8]
Numbering and naming
This minor planet was numbered by the Minor Planet Center on 7 February 2012 (M.P.C. 78220).[9] As of 2025[update], it has not been named.[2] If named, it will follow the naming scheme already established with 385571 Otrera and 385695 Clete, which is to name these objects after figures related to the Amazons, an all-female warrior tribe that fought in the Trojan War on the side of the Trojans against the Greek.[10]