  Solar prominences, intricate structures on the Sun's limb, have been a
subject of fascination due to their thread-like features and dynamic behaviors.
Utilizing data from the New Vacuum Solar Telescope (NVST), Chinese H_alpha
Solar Explorer (CHASE), and Solar Dynamics Observatory (SDO), this study
investigates the transverse swaying motions observed in the vertical threads of
a solar prominence during its eruption onset on May 11, 2023. The transverse
swaying motions were observed to propagate upward, accompanied by upflowing
materials at an inclination of 31 degrees relative to the plane of the sky.
These motions displayed small-amplitude oscillations with corrected velocities
of around 3-4 km/s and periods of 13-17 minutes. Over time, the oscillations of
swaying motion exhibited an increasing pattern in displacement amplitudes,
oscillatory periods, and projected velocity amplitudes. Their phase velocities
are estimated to be about 26-34 km/s. An important finding is that these
oscillations'phase velocities are comparable to the upward flow velocities,
measured to be around 30-34 km/s. We propose that this phenomenon is associated
with negative-energy wave instabilities, which require comparable velocities of
the waves and flows, as indicated by our findings. This phenomenon may
contribute to the instability and observed disruption of the prominence. By
using prominence seismology, the Alfven speed and magnetic field strength of
the vertical threads have been estimated to be approximately 21.5 km/s and 2
Gauss, respectively. This study reveals the dynamics and magnetic properties of
solar prominences, contributing to our understanding of their behavior in the
solar atmosphere.
