Using the high-resolution observations from New Vacuum Solar Telescope ( NVST ) jointly with the Solar~ { } Dynamics~ { } Observatory data , we investigate two successive confined eruptions ( Erup1 and Erup2 ) of a small filament in a decaying active region on 2017 November 10 .
During the process of Erup1 , the overlying magnetic arcade is observed to inflate with the rising filament at beginning and then stop the ongoing of the explosion .
In the hot EUV channel , a coronal sigmoidal structure appears during the first eruption and fade away after the second one .
The untwisting rotation and disintegration of the filament in Erup2 are clearly revealed by the NVST H \alpha intensity data , hinting at a pre-existing twisted configuration of the filament .
By tracking two rotating features in the filament , the average rotational angular velocity of the unwinding filament is found to be \sim 10.5 \degr min ^ { -1 } .
A total twist of \sim 1.3 \pi is estimated to be stored in the filament before the eruption , which is far below the criteria for kink instability .
In the course of several hours prior to the event , some photospheric flux activities , including the flux convergence and cancellation , are detected around the northern end of the filament , where some small-scale EUV brightenings are also captured .
Moreover , strongly-sheared transverse fields are found in the cancelling magnetic features from the vector magnetograms .
Our observational results support the flux cancellation model , in which the interaction between the converging and sheared opposite-polarity fluxes destabilizes the filament and triggers the ensuing ejection .