  We conducted a satellite search around the dwarf planet 1 Ceres using Hubble
Space Telescope and ground-based Palomar data. No candidate objects were found
orbiting Ceres in its entire stability region down to ~500km from the surface
of Ceres. Assuming a satellite would have the same albedo as Ceres, which has a
visual geometric albedo of 0.07-0.10, our detection limit is sensitive to
satellites larger than 1-2 km in diameter.
