Dynamical past evolution of the nominal orbit of C/2015 XY1. Here P0506 and P0230 are excluded from the model. Changes in a perihelion distance (green), an inclination (fuchsia) and an argument of perihelion (red) are shown. The thick lines depict the result of the full dynamical model while thin lines show the evolution of elements in the absence of any stellar perturbations. Angular elements are expressed in the Galactic frame.