2015 TG387

541132 Leleākūhonua, provisionally designated 2015 TG387, is an extreme trans-Neptunian object and sednoid in the outermost part of the Solar System. It was first observed on 13 October 2015, by astronomers at the Mauna Kea Observatories, Hawaii. Based on its discovery date near Halloween and the letters in its provisional designation 2015 TG387, the object was informally nicknamed "The Goblin" by its discoverers and later named Leleākūhonua, comparing its orbit to the flight of the Pacific golden plover. It was the third sednoid discovered, after Sedna and 2012 VP113, and measures around 220 kilometers (140 miles) in diameter. 
Leleākūhonua orbits the Sun at a distance of 65–2000 AU once roughly every 32,000 years (semi-major axis of ~1080 AU). Its orbit has a very high eccentricity of 0.94 and an inclination of 12° with respect to the ecliptic. It belongs to the extreme trans-Neptunian objects defined by their large semi-major axis and is the third sednoid ever to be discovered, after Sedna and 2012 VP113 ("Biden"). Along with the similar orbits of other distant trans-Neptunian objects, the orbit of Leleākūhonua suggests, but does not prove, the existence of a hypothetical Planet Nine in the outer Solar System.
Category:Trans-Neptunian objects