# Interaction of two filaments in a long filament channel associated with twin coronal mass ejections

## TL;DR

This study investigates the interaction of two solar filaments leading to twin coronal mass ejections, revealing magnetic flux changes, filament dynamics, and the role of magnetic topology in CME propagation.

## Contribution

It provides new insights into how filament interactions and magnetic topology contribute to the formation of twin CMEs, based on high-resolution solar observations.

## Key findings

- Filament interaction triggered twin CMEs.
- Magnetic flux cancellation preceded eruption.
- Magnetic topology influenced CME propagation direction.

## Abstract

Using the high-quality observations of the Solar Dynamics Observatory, we present the interaction of two filaments (F1 and F2) in a long filament channel associated with twin coronal mass ejections (CMEs) on 2016 January 26. Before the eruption, a sequence of rapid cancellation and emergence of the magnetic flux has been observed, which likely triggered the ascending of the west filament (F1). The east footpoints of rising F1 moved toward the east far end of the filament channel, accompanying with post-eruption loops and flare ribbons. It likely indicated a large-scale eruption involving the long filament channel, resulted from the interaction between F1 and the east filament (F2). Some bright plasma flew over F2, and F2 stayed at rest during the eruption, likely due to the confinement of its overlying lower magnetic field. Interestingly, the impulsive F1 pushed its overlying magnetic arcades to form the first CME, and F1 finally evolved into the second CME after the collision with the nearby coronal hole. We suggest that the interaction of F1 and the overlying magnetic field of F2 led to the merging reconnection that form a longer eruptive filament loop. Our results also provide a possible picture of the origin of twin CMEs, and show the large-scale magnetic topology of the coronal hole is important for the eventual propagation direction of CMEs.