Exploring Magnetic Star-Planet Interactions in CARMENES targets Using Radio Observations

Magnetic star–planet interaction (SPI) in the sub-Alfvénic regime can channel Poynting flux back to the host star and potentially power highly circularly polarised, time-variable electron–cyclotron maser (ECM) emission. Here we present multi-epoch uGMRT Band 4 observations aimed at searching for SPI-driven emission from nearby CARMENES systems (GJ 806, GJ 436, and CD Cet). Our preliminary results show non-detections for all of these CARMENES systems. We then revisit GJ 486 using the latest public release of our SIRIO code, extending our published uGMRT analysis by (i) exploring a large range of efficiencies in the conversion of Poynting flux into radio emission, β, and stellar mass-loss rates; and (ii) incorporating additional interaction prescriptions and wind/magnetic geometries. The resulting exclusion maps directly show how uGMRT non-detections constrain the allowed combinations of stellar mass-loss rate and β, and highlight which modelling assumptions dominate the inference.