Understanding the Role of Mass-Unloading in Filament Eruptions

TL;DR

This study investigates how mass-unloading influences filament eruptions on the Sun, using multi-viewpoint observations to quantify the mass loss and its effect on eruption dynamics.

Contribution

It demonstrates the importance of mass-unloading in filament eruptions and provides quantitative analysis linking plasma mass loss to eruption mechanics.

Findings

Mass-unloading accounts for 70% of filament mass evacuation.

A gravitational to magnetic tension force ratio of 1.8 to 4.1 was observed.

Mass-unloading restrains radial expansion until significant mass is evacuated.

Abstract

We describe a partial filament eruption on 11 December 2011 which demonstrates that the inclusion of mass is an important next step for understanding solar eruptions. Observations from the \textit{Solar Terrestrial Relations Observatory Behind} (STEREO-B) and the \textit{Solar Dynamics Observatory} (SDO) spacecraft were used to remove line-of-sight projection effects in filament motion and correlate the effect of plasma dynamics with the evolution of the filament height. Flux cancellation and nearby flux emergence are shown to have played a role in increasing the height of the filament prior to eruption. The two viewpoints allow the quantitative estimation of a large mass-unloading, the subsequent radial expansion, and the eruption of the filament to be investigated. A 1.8 to 4.1 lower-limit ratio between gravitational and magnetic tension forces was found. We therefore conclude that following the loss-of-equilibrium of the flux rope, the radial expansion of the flux rope was restrained by the filamentary material until 70\% of the mass had evacuated the structure through mass-unloading.