The noneruptive reconfiguration of a quiescent filament after a nearby active region emergence

Abstract

The unpredictability of solar filament eruptions presents major challenges for forecasting space weather, since such eruptions frequently drive coronal mass ejections that impact the heliosphere. While nearby flux emergence is often linked to their destabilization, the specific characteristics of both the emerging flux and the filament that determine whether an eruption occurs remain unclear. We report observations of a quiescent filament that did not erupt following the nearby emergence of active region NOAA 13270 and a subsequent C-class flare in 2023 April. Our analysis combines multiviewpoint extreme ultraviolet (EUV) imaging and X-ray imaging with EUV spectroscopy, radio imaging, and measurements of, and extrapolations from, the photospheric magnetic field. We identify the formation of a coronal null point and fan-spine topology at the interface between the active region and filament which exhibited persistent slow reconnection, indicated by chromospheric brightenings, persistent radio emission, and plasma upflows. Our results indicate that ongoing reconnection and jets can relieve magnetic stress and enable filament stability, even when under strong perturbation. We suggest that the orientation of emerging flux relative to the ambient field is a critical parameter in filament evolution and we provide observational constraints for models of filament stability and eruption.