Setebos is a small, dark moon (about 48 km in diameter, assuming an albedo of 0.04) which orbits Uranus in the opposite direction from the regular
moons and the planet's rotation (known as a retrograde orbit). It is one of the farthest moons from Uranus, orbiting its home planet at a distance of more than 17 million km. Its orbital characteristics are similar to those of Prospero and Sycorax, suggesting a common origin. But its gray color differs from the light red of Sycorax, implying a different origin.
Setebos was discovered on 18 July 1999 by John J. Kavelaars, Brett Gladman, Matthew Holman, Jean-Marc Petit, and Hans Scholl Using the Canada-France-Hawaii Telescope at the Mauna Kea Observatory on the island of Hawaii. They discovered Prospero and Stephano at the same time.
How Setebos Got its Name:
Originally called S/1999 U1, Setebos was the name of a South American (Patagonian) deity, which William Shakespeare used as the god worshipped by Sycorax the witch and her son Caliban in the play, "The Tempest."
Moons of Uranus are named for characters in Shakespeare's plays and from Alexander Pope's "Rape of the Lock."