Covariance between the position angle of the ascending node Ω and inclination i, and corresponding marginalized distributions, of the photocenter orbit of the π Men system from the MCMC calculation using only the HIPPARCOS measurements (black) and using all available astrometry (red). Contours denote areas encompassing 68, 95, and 99.7% of the probability. Marginalized 1σ credible intervals are indicated. The values of i and Ω from the maximum likelihood analyses are shown for reference (cross symbols). The orbital inclination of π Men b is significantly different from that of the inner planet (blue dotted line), indicating that the system is not aligned.