A comparative study between a failed and a successful eruption initiated from the same polarity inversion line in AR 11387

TL;DR

This study compares a failed and a successful solar eruption from the same region, identifying key magnetic and force-related factors that determine eruption outcomes.

Contribution

It provides a detailed analysis of the magnetic conditions and forces influencing eruption success or failure from the same polarity inversion line.

Findings

Weaker non-potentiality correlates with failed eruptions.

Larger magnetic flux ratio and stable regions confine eruptions.

Smaller Lorentz force impulse results in slower ejecta.

Abstract

In this paper, we analyzed a failed and a successful eruption that initiated from the same polarity inversion line within NOAA AR 11387 on December 25, 2011. They both started from a reconnection between sheared arcades, having distinct pre-eruption conditions and eruption details: before the failed one, the magnetic fields of the core region had a weaker non-potentiality; the external fields had a similar critical height for torus instability, a similar local torus-stable region, but a larger magnetic flux ratio (of low corona and near-surface region) as compared to the successful one. During the failed eruption, a smaller Lorentz force impulse was exerted on the outward ejecta; the ejecta had a much slower rising speed. Factors that might lead to the initiation of the failed eruption are identified: 1) a weaker non-potentiality of the core region, and a smaller Lorentz force impulse gave the ejecta a small momentum; 2) the large flux ratio, and the local torus-stable region in the corona provided strong confinements that made the erupting structure regain an equilibrium state.