(309239) 2007 RW₁₀ (provisional designation 2007 RW₁₀) is a temporary quasi-satellite of Neptune.^[3] Observed from Neptune, it would appear to revolve around it over one Neptunian year but in reality, it orbits the Sun, not Neptune.

(309239) 2007 RW₁₀ was discovered by the Palomar Distant Solar System Survey on September 9, 2007,^[4][5] with precovery images from 1988 (also taken at Palomar).^[6] At the time of discovery, this minor body was believed to be a Neptune trojan,^[7] but it is no longer listed as such.^[8][9] The Jet Propulsion Laboratory classifies (309239) 2007 RW₁₀ as trans-Neptunian object but the Minor Planet Center includes the object among centaurs. It moves in an orbit with an inclination of 36.2°, a semi-major axis of 30.18 AU, and an eccentricity of 0.3020.^[1] Herschel-PACS observations indicate that it has a diameter of 247 km.^[2]

(309239) 2007 RW₁₀ is currently following a quasi-satellite loop around Neptune.^[3] It has been a quasi-satellite of Neptune for about 12,500 years and it will remain in that dynamical state for around another 12,500 years.^[3] Prior to the quasi-satellite dynamical state, (309239) 2007 RW₁₀ was an L₅ trojan and it will return to this state soon after leaving its current quasi-satellite orbit. Its orbital inclination is the largest among known Neptune co-orbitals. It is also possibly the largest known object trapped in the 1:1 mean-motion resonance with any major planet.

(309239) 2007 RW₁₀ is a dynamically hot (both, high eccentricity and inclination) object that is unlikely to be a primordial Neptune co-orbital. It probably originated well beyond Neptune and was later temporarily captured in the 1:1 resonance with Neptune.^[3][10]

• 2005 TN74, which was also suspected of being a Neptune trojan at the time of discovery