(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.

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]

Numbering and naming

Due to its orbital uncertainty, this minor planet has not been numbered and its official discoverers have not been determined.^[1][2] 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.^[6]