(612095) 1999 OJ4

(612095) 1999 OJ4 is a trans-Neptunian object and binary system from the classical Kuiper belt, located in the outermost region of the Solar System. The bright cubewano belongs to the cold population and measures approximately 75 kilometers (47 miles) in diameter. It was first observed at Mauna Kea Observatory on 18 July 1999. Discovered in 2005, its moon is just 3 kilometers smaller than its primary and has an orbital period of 84 days. == Orbit and classification == 1999 OJ4's orbit characterizes it as a classical Kuiper Belt object, or cubewano. Due to its nearly circular orbit and low inclination, it is also in the "cold" population of cubewanos. As a result, it is likely reddish in color. == Satellite == 1999 OJ4 has one moon. This moon was discovered by the Hubble Space Telescope on 5 October 2013. It orbits 3306±17 km away from 1999 OJ4, completing one orbit every 84.1147±0.0050 d. The orbit has an eccentricity of 0.3683±0.0038. At about 72 km, it is nearly the same size as 1999 OJ4. From the surface of 1999 OJ4, it would have an apparent diameter of roughly 8.11°, over fourteen times the apparent size of the Sun from Earth. == Notes == == References == == External links == 1999 OJ4 – System parameters, Lowell Observatory List of Transneptunian Objects, Minor Planet Center List of binary asteroids/TNOs, Johnston's Archive Asteroid Lightcurve Database (LCDB), query form (info Archived 16 December 2017 at the Wayback Machine) (612095) 1999 OJ4 at AstDyS-2, Asteroids—Dynamic Site Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info (612095) 1999 OJ4 at the JPL Small-Body Database