Discovery of a Low-Eccentricity, High-Inclination Kuiper Belt Object at 58 AU

We report the discovery of the first trans-Neptunian object, designated 2004 XR190, with a low-eccentricity orbit beyond the 2 : 1 mean motion resonance. Fitting an orbit to 23 astrometric observations spread out over 12 months yields an orbit of a = 57.2 ± 0.4, e = 0.08 ± 0.04, and i = 46.°6. All viable orbits have perihelia distances q > 49 AU. The very high orbital inclination of this extended scattered disk object might be explained by several models, but its existence again points to a large as-yet undiscovered population of trans-Neptunian objects with large orbital perihelia and inclination.