You said "planet", in quotes, but Sedna is not a planet. To quote your link, "Sedna is not even officially a planet at all."

Even Pluto is no longer a planet.

>actually sedna is a "planet" on its own much further out than pluto
>http://www.nineplanets.org/sedna.html
>pluto does have a couple of moons but one one is named.
>http://science.nasa.gov/headlines/y2005/01nov_moonsofpluto.htm
>~M