Dynamical Mass Constraints on Transition Disk Perturbers Using the G23H Catalog

We present dynamical mass constraints on perturbers in 11 transition disk systems using a novel combination of calibrated Hipparcos and Gaia absolute astrometry data. Out of the sample of 11, we find support for companions in four systems, with significant detections in two. These systems are HD 142527, where we clearly detect the known low-mass stellar companion HD 142527 B and MWC 758, where we detect a likely substellar companion. We also find moderate evidence of companions to AB Aur and UX Tau A. For the seven systems with nondetections, we find no evidence for companions more massive than ∼12 M Jup with a semimajor axis greater than 3 au for both HD 100546 and HD 100453, nor for companions more massive than ∼3 M Jup with a semimajor axis greater than 2 au for TW Hya. We also find no evidence for stellar-mass companions with semimajor axes between ∼4 and ∼25 au for HD 34282, HD 97048, CQ Tau, and RY Lup. In addition to our fiducial model, we perform cross-validation between astrometry sources. By comparing results across models, we find tentative evidence of a short-timescale excess astrometric noise that may impact some protoplanetary disk systems. We conclude with predictions for the prospects of making dynamical mass constraints on protoplanets in protoplanetary disk systems with Gaia Data Release 4 (GDR4) using detailed simulations of GDR4 data of PDS 70 and WISPIT 2.