2015 RY245, also known as o5s13, is a trans-Neptunian object from the scattered disc of the outermost reaches of the Solar System, approximately 78 kilometers in diameter. It was discovered on 9 September 2015, by the Outer Solar System Origins Survey using the Canada–France–Hawaii Telescope at Mauna Kea Observatories, Hawaii, United States. It is one a small number of detached objects with perihelion distances of 30 AUs or more, and semi-major axes of 200 AU or more. Such objects can not reach such orbits without some perturbing object, which lead to the speculation of planet nine.