Coherent radio bursts from known M-dwarf planet-host YZ Ceti

Abstract Observing magnetic star–planet interactions (SPIs) offers promise for determining the fields of exoplanets. Models sub-Alfvénic SPIs predict that terrestrial planets in close-in orbits around M dwarfs can induce detectable stellar radio emission, manifesting as bursts strongly polarized coherent radiation observable at specific planet orbital positions. Here we present 2–4 GHz detections on slowly rotating dwarf YZ Ceti, which hosts a compact system planets, innermost with two-day period. Two occur similar phases Ceti b, suggestive an enhanced probability near phase. We model system’s magnetospheric environment context and determine b plausibly power observed flux densities detections. However, cannot rule out activity without well-characterized rate non-planet-induced slow rotators. is therefore candidate SPI system, unique target long-term monitoring.