Sedna is a planetoid that is currently classified as being in the scattered disc of objects that overlaps and extends beyond the Kuiper belt, although some astronomers believe it may actually be part of the Oort cloud. It is not yet known whether Sedna has been made spherical by its own gravity; if this is eventually determined to be the case, it will be classified as a dwarf planet.
Sedna has a highly elongated orbit, with an orbital eccentricity of 0.85. Its distance from the Sun ranges from 76.36 AU at perihelion to 960.78 AU at aphelion, with an average of 518.57 AU. Its orbit is tilted 11.93° relative to Earth's. It takes Sedna 11,809 Earth-years to revolve once around the Sun.
Sedna's rotational period is the subject of substantial uncertainty, but may be about 10 hours.