Title: Measuring the radius and mass of Planet Nine,
Abstract: Batygin and Brown (2016) have suggested the existence of a new Solar System
planet supposed to be responsible for the perturbation of eccentric orbits of
small outer bodies. The main challenge is now to detect and characterize this
putative body. Here we investigate the principles of the determination of its
physical parameters, mainly its mass and radius. For that purpose we
concentrate on two methods, stellar occultations and gravitational microlensing
effects (amplification, deflection and time delay). We estimate the main
characteristics of a possible occultation or gravitational effects: flux
variation of a background star, duration and probability of occurence. We
investigate also additional benefits of direct imaging and of an occultation.