Q Quaoar - Discovered in 2002. Dwarf planet/Kuiper Belt object, which is out beyond the orbit of Neptune. About half the size of Pluto (see previous entry). Unlike Pluto , it has a fairly circular orbit, that is close to the plane of the major planets, so it may have been trundling along out there since the early days of the solar system. Can't be seen without a powerful telescope. It takes 286 years to complete its orbit of the Sun (Pluto takes 248 years). Unlike Pluto, its orbit doesn't cross that of Neptune. In recent times Pluto has spent some years closer to the Sun than Neptune is , but Quaoar doesn't do that. By the way Pluto's orbit is in stable "resonance" with that of Neptune, so although their paths cross , they won't crash (Phew!)
Another dwarf planet, nicknamed "Farfarout" , has recently been discovered that is even way beyond Quaoar, and takes abour a thousand years to orbit the Sun!