Possible constraints on exoplanet magnetic field strengths from planet-star interaction

摘要: A small percentage of normal stars harbor giant planets that orbit within a few tenths an astronomical unit. At such distances the potential exists for significant tidal and magnetic field interaction resulting in energy dissipation may manifest as changes stellar corona. We examine X-ray emission hosting find positive correlation between luminosity projected mass most closely orbiting exoplanets. investigate possible systematics observational biases could mimic or confuse this but no strong evidence any, especially more massive than ~0.1 MJ. Luminosities upper limits are consistent with interpretation there is lower floor to dependent on close-in planetary mass. Under hypothesis consequence planet-star interaction, dissipation, we estimate strength increase 1 10 MJ factor ~8. Intriguingly, recent geodynamo scaling law predictions. The high-energy photon systems therefore provide unique access detailed magnetic, hence geodynamic, properties