  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.
