It was first observed on 29 April 2011, during the New Horizons KBO Search (268) using the Magellan II (Clay) Telescope at Las Campanas Observatory in Chile.
[3] Based on a generic magnitude-to-diameter conversion, it measures approximately 100 kilometers in diameter using an absolute magnitude of 8.1 and an assumed albedo of 0.10.
[4] It is an averaged-sized body among the first 17 Neptune trojans discovered so far, which measure between 60 and 200 kilometers (for an absolute magnitude of 9.3–6.6 and an assumed albedo of 0.10).
Due to the variable color classification of this object, it is suspected that inhomogeneities in the surface composition exist.
The New Horizons team eventually decided that they would not target 2011 HM102 for observations because the preparations for the Pluto approach took precedence.