(505478) 2013 UT15 is an extreme trans-Neptunian object from the scattered disc, located in the outermost regions of the Solar System, approximately 260 kilometers (160 miles) in diameter.
It was discovered on 2 August 2013, by astronomers of the Outer Solar System Origins Survey at Mauna Kea Observatory, Hawaii, United States.
The object is estimated to have a bluish spectra (BB).
[6] 2013 UT15 has been estimated to measure 243 and 340 kilometers in diameter, based on an assumed albedo of 0.09 and 0.04, respectively.
[3][6] A generic magnitude-to-diameter conversion gives a mean-diameter of 260 kilometers,[5] using with a typical albedo of 0.08 and a published absolute magnitude of 6.2951.