The asteroid was discovered on 18 August 1993, by Belgian astronomer Eric Elst at CERGA (010) in Caussols, southeastern France.
[2] Justinehénin orbits the Sun in the outer main-belt at a distance of 2.8–3.6 AU once every 5 years and 9 months (2,091 days).
[4] Based on an absolute magnitude of 13.2,[1] Justinehénin potentially measures between 6 and 14 kilometers in diameter, assuming an albedo in the range of 0.05 to 0.25.
[3] Since asteroids in the outer main-belt are mostly of a carbonaceous rather than of a silicaceous composition, with low albedos, typically around 0.06, Justinehénin's diameter might be on the upper end of NASA's published conversion table, as the lower the body's reflectivity (albedo), the larger its diameter at a constant absolute magnitude (brightness).
[3] As of 2017, the asteroid's effective size, its composition and albedo, as well as its rotation period and shape remain unknown.