90482 Orcus This means that Orcus is currently viewed pole-on, which could explain the near absence of any rotational modulation of its brightness. If, however, the primary is tidally locked with the satellite, the rotational period will coincide with the 9.7-day orbital period of Vanth. This minor planet was named after one of the Roman gods of the underworld, Orcus. While Pluto was the ruler of the underworld, Orcus was a punisher of the damned. The approved naming citation was published by the Minor Planet Center on 26 November 2004 (). Under the guidelines of the International Astronomical Union's (IAU) naming conventions,
90482 Orcus quoted Taaffe as saying that if Vanth "accompanies dead souls from the moment of death to the underworld itself, then of course her face is turned always toward Orcus", a reference to the likely synchronous orbit of Vanth about Orcus. 90482 Orcus 90482 Orcus ( ), provisional designation , is a trans-Neptunian object from the Kuiper belt with a large moon, Vanth. It was discovered on 17 February 2004, by American astronomers Michael Brown of Caltech, Chad Trujillo of the Gemini Observatory, and David Rabinowitz of Yale University. It is probably a dwarf planet. Precovery images taken by the Palomar