SDO/AIA Observations of Large-Amplitude Longitudinal Oscillations in a Solar Filament

TL;DR

This study reports on large-amplitude longitudinal oscillations in a solar filament observed by SDO/AIA, revealing their characteristics, triggers, and associated eruptions, providing insights into the magnetic structure and dynamics of solar filaments.

Contribution

First detailed observation of LAL oscillations in a solar filament using SDO/AIA, analyzing their behavior, triggers, and relation to filament eruption and magnetic structure.

Findings

Oscillations have periods of 44-67 minutes.

Oscillations can persist for multiple cycles without damping.

Filament eruption is associated with oscillation transition and CMEs.

Abstract

We present the first \emph{Solar Dynamics Observatory}/Atmospheric Imaging Assembly observations of the large-amplitude longitudinal (LAL) oscillations in the south and north parts (SP and NP) of a solar filament on 2012 April 7. Both oscillations are triggered by flare activities close to the filament. The period varies with filamentary threads, ranging from 44 to 67 min. The oscillations of different threads are out of phase, and their velocity amplitudes vary from 30 to 60 km s$^{-1}$, with a maximum displacement of about 25 Mm. The oscillations of the SP repeat for about 4 cycles without any significant damping and then a nearby C2.4 flare causes the transition from the LAL oscillations of the filament to its later eruption. The filament eruption is also associated with a coronal mass ejection and a B6.8 flare. However, the oscillations of the NP damp with time and die out at last. Our observations show that the activated part of the SP repeatedly shows a helical motion. This indicates that the magnetic structure of the filament is possibly modified during this process. We suggest that the restoring force is the coupling of the magnetic tension and gravity.