90482 Orcus

90482 Orcus (symbol: ), originally known by the provisional designation 2004 DW, is a Kuiper belt object (KBO). It is also a dwarf planet. It was found by Michael Brown, Chad Trujillo and David Rabinowitz on February 17, 2004. It was also seen in pictures from November 8, 1951. Like Pluto it is in orbital resonance with Neptune but it stays on the opposite side of the Sun from Pluto.
Moon.
A moon of Orcus was found on 22 February 2007.
The satellite was found at 0.25 arcsec from Orcus with magnitude difference of 2.7. Assuming an albedo similar to that of the primary, the magnitude suggests a diameter of about 220 km. It is thought to be a smaller KBO that was captured.