Sedna's highly eccentric orbit with its closest approach to the Sun at 76 AU is dynamically detached from Neptune and with its furthest point in its orbit located at roughly 1000 AU, Sedna is too far away from the edge of the Solar System to feel the effects of passing stars in the current solar environment. (sen.com)
Galactic tides and gravitational nudges from passing stars in the current solar environment, can perturb objects in the Oort cloud and send them in on orbits towards the inner Solar System as comets, but Sedna and this new discovery are effectively cut off from the rest of the solar system. (megschwamb.com)
They come in a variety of shapes, colors, and sizes, many with their own moons, some in peculiar orbits that have been pushed by Neptune or pulled by passing stars. (discovermagazine.com)