Coexistence of Decaying and Decayless Kink Oscillations in a Bundle of Coronal Loops Triggered by an X6.3 Solar Flare

We report the coexistence of decaying and decayless kink oscillations within a single bundle of coronal loops during the X6.3-class solar flare on 2024 February 22. Using coordinated observations from Geostationary Operational Environmental Satellite, Solar Dynamics Observatory/Atmospheric Imaging Assembly, Advanced Space-based Solar Observatory, and New Vacuum Solar Telescope, we analyze five flare-activated coronal loops (S1–S5) and identify distinct oscillation regimes in different segments. Time–distance and curve-fitting analyses of the five selected coronal loops reveal a broad range of oscillation amplitudes (1.1–7.1 Mm) and periods (119–630 s). In loop S2, decayless oscillations with a period of 274.6 ± 1.0 s and nearly constant amplitude are observed to coexist for a period of time with rapidly decaying oscillations of a similar period, 271.1 ± 1.7 s. The differential emission measure diagnostics indicate strong spatial variation in magnetic field strength, decreasing from 30 G near the flare core to 11 G in the peripheral loops. These variations in oscillation regimes and magnetic field strength imply that the local plasma environment strongly influences wave decaying processes. These results suggest that magnetic topology and local plasma conditions play a key role in modulating the wave decaying behavior.