A Time Series of Filament Eruptions Observed by Three Eyes from Space: From Failed to Successful Eruptions

TL;DR

This study uses stereoscopic observations from space and ground to analyze six filament eruptions, revealing that energy release in the low corona determines whether an eruption results in a CME or fails, despite similar magnetic confinement.

Contribution

It demonstrates that low corona energy release, rather than magnetic confinement, is key to successful filament eruptions with CMEs, based on multi-viewpoint observations.

Findings

Successful eruption has higher flare intensity and filament velocity.

Filament velocities are proportional to flare powers.

Magnetic confinement is similar in failed and successful eruptions.

Abstract

We present stereoscopic observations of six sequent eruptions of a filament in the active region NOAA 11045 on 2010 Feb 8, with the advantage of the STEREO twin viewpoints in combination with the earth viewpoint from SOHO instruments and ground-based telescopes. The last one of the six eruptions is with a coronal mass ejection, while the others are not. The flare in this successful one is more intensive than in the others. Moreover, the filament material velocity of the successful one is also the largest among them. Interestingly, all the filament velocities are found proportional to their flare powers. We calculate magnetic field intensity at low altitude, the decay indexes of the external field above the filament, and the asymmetry properties of the overlying fields before and after the failed eruptions and find little difference between them, indicating the same coronal confinement for the failed and the successful eruptions. The results suggest that, besides the confinement of coronal magnetic field, the energy released in low corona should be another crucial element for production of a failed or successful filament eruption. That is, only a coronal mass ejection can be launched away if the energy released exceeds some critical value, given the same coronal conditions.