Unaccounted for mass in the Solar System?

[More Boosters]

Maybe I am overestimating how accurately, if at all, we can locate the solar system's barycenter, but it occurred to me that, if we have a way to measure it other than just plugging the numbers with all the bodies we have, we might know how much mass in the solar system there is that we haven't accounted for. Am I making sense?

[ZetaX]

While theoretically correct, we are pretty sure that the amount not accounted for is very small. We do not see any relevant amounts of mass, and we are not observing any unexplained irregularities in the orbits of planets.

It probably has nonetheless been measured anyway.

[Findthepin1]

[quote name='ZetaX']We are not observing any unexplained irregularities in the orbits of planets.[/QUOTE]
Sedna?

[ZetaX]

[quote name='Findthepin1']Sedna?[/QUOTE]

There is no unexplained irregularity in Sedna's orbit. It follows its path as predicted. That it has a rather non-standard elongation has nothing to do with unaccounted mass.

[Shpaget]

A mostly uniform disk shaped asteroid belt, such as main belt and Kuiper belt and spherical formation such as Oort cloud will not alter the position of the barycenter.