Pre-eruption Oscillations in Thin and Long Features in a Quiescent Filament

TL;DR

This study examines pre-eruption oscillations in a quiescent solar filament, linking magnetic flux changes and filament barbs to eruption initiation, providing insights into early warning signs of solar eruptions.

Contribution

It identifies the role of magnetic flux cancellation and filament barbs in pre-eruption oscillations, offering a new interpretation of filament eruption mechanisms.

Findings

Oscillations observed in filament barbs before eruption

Magnetic flux cancellation at filament footpoints

Gradual loss of equilibrium leading to eruption

Abstract

We investigate the eruption of a quiescent filament located close to an active region. Large-scale activation was observed in only half of the filament in the form of pre-eruption oscillations. Consequently only this half erupted nearly 30 hr after the oscillations commenced. Time-slice diagrams of 171 \AA\ images from Atmospheric Imaging Assembly were used to study the oscillations. The oscillations were observed in several thin and long features connecting the filament spine to the chromosphere below. This study traces the origin of such features and proposes their possible interpretation. Small-scale magnetic flux cancellation accompanied by a brightening was observed at the footpoint of the features shortly before their appearance, in images recorded by the Helioseismic and Magnetic Imager. Slow rise of the filament was detected in addition to the oscillations, indicating a gradual loss of equilibrium. Our analysis indicates that a change in magnetic field connectivity between two neighbouring active regions and the quiescent filament resulted in weakening of the overlying arcade of the filament leading to its eruption. It is also suggested that the oscillating features are filament barbs, and the oscillations are a manifestation during the pre-eruption phase of filaments.