High-Resolution Imaging Required to Validate 72% of TESS Small-Planet Candidates

An automated TRICERATOPS pipeline was run on 443 TESS planet candidates, recomputing false-positive probabilities for the 264 objects that possessed high-resolution imaging contrast curves both with and without those data. Removal of the curves raised FPPs enough to invalidate 49 of the 68 previously validated planets. The dependence is size-dependent: every validated planet smaller than 1.7 Earth radii required imaging, while only one-third of those larger than 4 Earth radii did. The analysis also delivered 64 new validated planets, four of which meet JWST transmission spectroscopy metrics solely because of their imaging constraints.

Earlier Kepler-era studies had shown that follow-up resources limit confirmed yields, yet none performed a systematic on-off test at population scale for TESS. The present work therefore supplies the first quantitative measure of imaging’s gatekeeping role and directly links resource scarcity to the supply of small planets available for atmospheric characterization.

Future wide-field surveys will inherit the same bottleneck unless high-resolution imaging capacity grows or statistical validation methods improve enough to compensate. Ground-based extreme-adaptive-optics systems and space-based interferometers now in development could relax the constraint, but only if allocated to the smallest-planet candidates that benefit most.

The 64 newly validated planets span 0.94–7.83 Earth radii; occurrence-rate and demographic studies that rely on this sample will therefore carry an implicit dependence on continued access to high-resolution imaging.