Observational Constraints on Planet Nine: Astrometry of Pluto and Other Trans-Neptunian Objects
Matthew J. Holman and Matthew J. Payne 2016 AJ 152 80
Astrometry of Pluto and other trans-Neptunian objects, used to constrain the location/distance/mass of a possible Planet Nine, suggests the planet is more massive or closer than was originally hypothesized.