Posterior distributions of orbital elements of the close companion in CHX 22 using the universal Keplerian variable code by Beust et al. (2016), with the possibility of unbound orbits (e > 1). In all plots, the red bars (for histograms) and the black stars (in correlation maps) stand for the best-χ² solution of the posterior distribution. For compatibility with unbound solutions, the first variable fitted is the periastron q instead of the semi-major axis a. The 180° periodicity of distributions of the longitude of ascending node (Ω) and the argument of periastron (ω) is a degeneracy inherent to the astrometric fit with no radial velocity data.