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 seven systems, with significant detections in three. These systems are: HD 142527, where we clearly detect the known low-mass stellar companion HD 142527 B; AB Aurigae, where we detect a low-mass stellar or sub-stellar companion; and MWC 758, where we detect a likely sub-stellar companion. We also find strong evidence of companions to HD 97048 and UX Tau A, and moderate evidence for companions to HD 100546 and CQ Tau. In the four systems with non-detections, we find no evidence for companions more massive than ∼6 MJup with a semi-major axis greater than 3 au for HD 100453, nor for companions more massive than ∼2 MJup with a semi-major axis greater than 2 au for TW Hya. We also find no evidence for stellar mass companions with semi-major axes between ∼3 and ∼25 au for both HD 34282 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 using detailed simulations of Gaia DR4 data of PDS 70 and WISPIT 2.
@article{arxiv.2602.07731,
title = {Dynamical Mass Constraints on Transition Disk Perturbers with the G23H Catalog},
author = {Dori Blakely and William Thompson and Doug Johnstone and Jessica Speedie and Jerry W. Xuan and Simon Blouin and Jingwen Zhang and Jean-Baptiste Ruffio and Eric Nielsen and Brendan P. Bowler and Kyle Franson and William Roberson and Ryan Cloutier and Andre Fogal and Kaitlyn Hessel and Christian Marois and Alexandra Rochon},
journal= {arXiv preprint arXiv:2602.07731},
year = {2026}
}