Destabilization of a Solar Prominence/Filament Field System by a Series of Eight Homologous Eruptive Flares

TL;DR

This study analyzes a series of eight homologous solar flares in active region NOAA 11237, revealing how repeated confined eruptions gradually destabilized a prominence/filament system, ultimately leading to a CME.

Contribution

It provides detailed multi-perspective observations of homologous flares and their role in destabilizing a prominence/filament system, linking repetitive eruptions to eventual CME occurrence.

Findings

Repeated homologous flares caused step-wise inflation of the prominence/filament cavity system.

Gradual destabilization from multiple eruptions led to a final ejective flare and CME.

The active region's eruptions influenced the magnetic field configuration and prominence stability.

Abstract

Homologous flares are flares that occur repetitively in the same active region, with similar structure and morphology. A series of at least eight homologous flares occurred in active region NOAA 11237 over 16 - 17 June 2011. A nearby prominence/filament was rooted in the active region, and situated near the bottom of a coronal cavity. The active region was on the southeast solar limb as seen from SDO/AIA, and on the disk as viewed from STEREO/EUVI-B. The dual perspective allows us to study in detail behavior of the prominence/filament material entrained in the magnetic field of the repeatedly-erupting system. Each of the eruptions was mainly confined, but expelled hot material into the prominence/filament cavity system (PFCS). The field carrying and containing the ejected hot material interacted with the PFCS and caused it to inflate, resulting in a step-wise rise of the PFCS approximately in step with the homologous eruptions. The eighth eruption triggered the PFCS to move outward slowly, accompanied by a weak coronal dimming. As this slow PFCS eruption was underway, a final ejective flare occurred in the core of the active region, resulting in strong dimming in the EUVI-B images and expulsion of a coronal mass ejection (CME). A plausible scenario is that the repeated homologous flares could have gradually destabilized the PFCS, and its subsequent eruption removed field above the acitive region and in turn led to the ejective flare, strong dimming, and CME.