541132 Leleākūhonua (), provisionally designated , 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 , 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 and , and measures around in diameter. Discovery Leleākūhonua was first observed on 13 October 2015 at the Mauna Kea Observatory , by American astronomers David Tholen, Chad Trujillo and Scott Sheppard during their astronomical survey for objects located beyond the Kuiper Cliff. The unofficial discovery was publicly announced on 1 October 2018. The survey uses two principal telescopes: For the Northern hemisphere, the 8.2-meter Subaru Telescope with its Hyper Suprime Camera at Mauna Kea Observatories, Hawaii, and for the Southern hemisphere, the 4-meter Blanco telescope and its Dark Energy Camera at Cerro Tololo Inter-American Observatory in Chile. For follow-up observations to determine an object's orbit, the astronomers are using the Magellan and the Discovery Channel telescopes. The survey's discoveries include , and . Orbit and classification Leleākūhonua orbits the Sun at a distance of 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 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 and ("Biden"). Implications of orbit 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. , the object is inbound 78 AU from the Sun; about two-and-a-half times farther out than Pluto's current location. It will come to perihelion (closest approach to the Sun) in 2078. As with Sedna, it would not have been found had it not been on the inner leg of its long orbit. This suggests that there may be many similar objects, most too distant to be detected by contemporary technological methods. Following the discovery of Leleākūhonua, Sheppard et al. concluded that it implies a population of about 2 million inner Oort cloud objects larger