OT, but I looked up the hypothetical parameters for hypothetical Planet 9.

It would only be about 10 Times Earth mass, or about 68% the size of Uranus, and only 2-4 times bigger than Earth in Diameter.

There is no way that Planet 9 Would clear its orbit.

Either call it Dwarf Planet 6 under the IAU, or Planet 15 if we go back to the “Spherical & Orbiting the sun definition. Because the IAU’s definition is bollocks.