(19308) 1996 TO66

' (provisional designation ') is a trans-Neptunian object that was discovered in 1996 by Chadwick Trujillo, David Jewitt and Jane Luu. Until 20000 Varuna was discovered, it was the second-largest known object in the Kuiper belt, after Pluto.

Origin
Based on their common pattern of IR water-ice absorptions, neutral visible spectrum and the clustering of their orbital elements, the other KBOs, , and  all appear to be collisional fragments broken off of the dwarf planet.

Orbit
The eccentricity of varies between ca. 0.110 and 0.125 every 2 million years, with additional variations on the order of ± 0.01 on much shorter time scales. It is in an intermittent 19:11 resonance with Neptune. The resonance breaks every 2 million years when the eccentricity is highest and the orbit is closest to Neptune.