Oort cloud (exo)planets

Abstract Dynamical instabilities among giant planets are thought to be nearly ubiquitous, and culminate in the ejection of one or more into interstellar space. Here we perform N-body simulations dynamical while accounting for torques from galactic tidal field. We find that a fraction would otherwise have been ejected instead trapped on very wide orbits analogous those Oort cloud comets. The ranges 1-10 per cent, depending initial planetary mass distribution. local density has modest effect trapping efficiency orbital radii planets. majority survive Gyr timescales. Taking account demographics exoplanets, estimate every 200-3000 stars could host an planet. This value is likely overestimate, as do not take place at early enough times affected by their stars’ birth cluster, planet stripping passing stars. If Solar System’s instability happened after cluster dissolution, there ∼7 cent chance ice was captured Sun’s cloud.