Probing the magnetic fields of starspots with transit mapping. II. Signatures of star-planet interaction

Starspots are surface manifestations of stellar magnetic activity and crucial probes of stellar dynamo processes. Here, we quantify the relationships between starspot properties and planetary parameters to identify star-planet interaction (SPI) signatures using compiled physical parameters from the transit mapping of ten FGK stars and one M star observed by the and space missions. We found significant correlations between the average magnetic field of starspots (Bavg) and planetary parameters. Most notably, Bavg correlates strongly with the SPI proxy RpPo (̊hoS!=!0.87, ̊hoP!=!0.79). Individual parameters also show significant trends, scaling positively with planetary radius (̊hoS!=!0.61) and negatively with semimajor axis (̊hoS!=!-0.61) and orbital period (̊hoS!=!-0.60). Importantly, these relationships remain statistically significant after controlling for stellar age, rotation period, and effective temperature via partial correlation analysis, with the correlation between Bavg and RpPo reaching ̊hoSpart!=!0.90. These results suggest that larger, close-in planets are associated with more intense starspot magnetic fields, potentially through magnetic coupling or tidal interactions modulating flux tube emergence. Kepler CoRoT