(613490) 2006 RJ103

(613490) 2006 RJ₁₀₃ is a Neptune trojan, first observed by the Sloan Digital Sky Survey Collaboration at Apache Point Observatory, New Mexico, on 12 September 2006.^[2] It was the fifth and largest such body discovered, approximately 180 kilometers in diameter. As of 2016^[update], it is 30.3 AU from Neptune.

(613490) 2006 RJ₁₀₃

Discovery[1][2]
Discovered by	Sloan Digital Sky Srvy.
Discovery site	Apache Point Obs.
Discovery date	12 September 2006
Designations
MPC designation	2006 RJ103
Minor planet category	Neptune trojan L4[3] centaur[1] distant[2]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 3
Observation arc	14.15 yr (5,169 days)
Aphelion	30.862 AU
Perihelion	28.988 AU
Semi-major axis	29.925 AU
Eccentricity	0.0313
Orbital period (sidereal)	163.70 yr (59,793 days)
Mean anomaly	251.55°
Mean motion	0° 0m 21.6s / day
Inclination	8.1641°
Longitude of ascending node	120.86°
Argument of perihelion	33.563°
Physical characteristics
Dimensions	130 km (est. at 0.10)[4] 180 km[5]
Apparent magnitude	22.0[5]
Absolute magnitude (H)	7.5[1]

Orbit and classification

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).

2006 RJ₁₀₃ belongs to the leading L₄ group, which follow 60° ahead Neptune's orbit. It orbits the Sun with a semi-major axis 29.925 AU of at a distance of 29.0–30.9 AU once every 163 years and 8 months (59,793 days). Its orbit has an eccentricity of 0.03 and an inclination of 8° with respect to the ecliptic.^[1]

Physical characteristics

The discoverers estimate that 2006 RJ₁₀₃ has a mean-diameter of 180 kilometers based on a magnitude of 22.0.^[5] Based on a generic magnitude-to-diameter conversion, it measures approximately 130 kilometers in diameter using an absolute magnitude of 7.5 with an assumed albedo of 0.10.^[4]

Ground-based and James Webb Space Telescope spectroscopy have shown that 2006 RJ₁₀₃ lacks clear signatures of water ice. Instead, its surface is covered by hydrated minerals that have 0.7 and 3.0 micron absorption features.^[6][7][8]

Numbering and naming

This minor planet was numbered by the Minor Planet Center on 28 March 2022 (M.P.C. 139905).^[9] If named, it will follow the naming scheme already established with 385571 Otrera, 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]