Composition of hydrated near-Earth object (100085) 1992 UY4

Near-infrared spectra of the near-Earth object (100085) 1992 UY4 are similar to those of P-type asteroids, providing a fitted geometric albedo of 0.052±0.0050.052±0.005 and an effective diameter of 1.68±0.08 km1.68±0.08 km. This object, with a likely outer-belt origin, also exhibits a 3-μm absorption feature with a band depth of 3%±1%3%±1%, corresponding to a regolithic bulk hydrogen-to-silicon ratio of 0.30±0.050.30±0.05. The bulk of this hydrogen seems to be present in H2O-dominated minerals.