Vanth, or 90482 Orcus I, is the single known natural satellite of the plutino and likely dwarf planet Orcus. It was discovered by Mike Brown and T.-A. Suer using discovery images taken by the Hubble Space Telescope on November 13, 2005. Read more
"S/1 90482 (2005)" is really not much a name as a license plate number. As does a license plate number, it tells you pretty much everything you need to know to identify the object in question. "S" is for satellite. "/1" means it is the first discovered. The "2005" at the end tells the date of discover, and the "90482" tells whose satellite it is, but only by yet another number. This number refers to the 90482nd minor planet (in the old terminology; no one quite knows what the new terminology is, but the numbers keep coming) to be officially recorded. That object is more commonly referred to as the large Kuiper belt object Orcus. We don't ever call the moon of Orcus by its official name of S/1 90482 (2005). Instead, around here, it is referred to mostly as "the moon of Orcus".
90482 Orcus (originally known by the provisional designation 2004 DW) is a Kuiper Belt object (KBO) and a likely dwarf planet that was discovered by Michael Brown of Caltech, Chad Trujillo of the Gemini Observatory, and David Rabinowitz of Yale University.