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

Abstract 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 ± 0.005 and an effective diameter of 1.68 ± 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 % , corresponding to a regolithic bulk hydrogen-to-silicon ratio of 0.30 ± 0.05 . The bulk of this hydrogen seems to be present in H2O-dominated minerals.

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