Detection of long-lasting aurora-like radio emission above a sunspot

We present our findings on long-lasting radio emissions above a sunspot, analogous to planetary auroral radio emissions. These emissions are typically characterized by highly polarized, intense radio bursts, generally attributed to electron cyclotron maser (ECM) emission from energetic electrons in regions with converging magnetic fields, such as planetary polar areas. Similar bursts have been observed in magnetically active low-mass stars and brown dwarfs, often prompting analogous interpretations. Here we report observations of long-lasting solar radio bursts with high brightness temperature, wide bandwidth, and high circular polarization fraction akin to these auroral and exo-auroral radio emissions, albeit two to three orders of magnitude weaker than those on certain low-mass stars. Our spatial, spectral, and temporal analysis indicate that the source is situated above a sunspot where a strong, converging magnetic field is present. The morphology and frequency dispersion of the source align with ECM emissions, likely driven by energetic electrons from recurring nearby solar flares. These observations provide new insights into the nature of intense solar radio bursts and suggest a potential model for understanding aurora-like radio emissions in other flare stars with significant starspots.