Mutual inclinations between giant planets and their debris discs in HD 113337 and HD 38529

HD 113337 and HD 38529 host pairs of giant planets, a debris disc, and wide M-type stellar companions. We measure the disc orientation with resolved images from Herschel and constrain the three-dimensional orbits of the outer planets with Gaia DR2 and Hipparcos astrometry. Resolved disc modelling leaves degeneracy in the disc orientation, so we derive four separate planet-disc mutual inclination ($\Delta I$) solutions. The most aligned solutions give $\Delta I=17-32\deg$ for HD 113337 and $\Delta I=21-45\deg$ for HD 38529 (both 1$\sigma$). In both systems, there is a small probability (
Comment: Accepted for publication in MNRAS