Positions of Irregular Uranian Moons

The observed positions (relative to Uranus) of S/1999 U 1, U 2, and U 3 on July 17, August 7, and Sept. 2 1999 are marked. For Caliban and Sycorax (the first two irregular satellites, discovered in 1997) the positions are marked at 10-day intervals between July 1 and October 15, 1999. The orbit of the outermost regular satellite, Oberon, is shown for reference, surrounding the planet (small dot).