A Universal Scaling between Damping Time and Period of Quasi-periodic Pulsations from Solar Extreme-Ultraviolet Brightenings to X-Ray Stellar Flares

Recent high spatial and temporal resolution extreme-ultraviolet (EUV) imaging observations have revealed that quasi-periodic pulsations (QPPs), a ubiquitous signature of impulsive energy release in solar and stellar flares, are also present in much smaller-scale coronal events known as EUV brightenings. Whether QPPs observed across such disparate spatial and energetic scales share a common physical origin remains an open question. Here we analyse 2146 EUV brightenings observed with Solar Orbiter/Extreme Ultraviolet Imager and 300 EUV solar flares observed with Solar Dynamics Observatory/Atmospheric Imaging Assembly, identifying 185 brightenings and 89 flares exhibiting statistically significant damped QPPs. We show that the relationship between damping time and oscillation period follows a common power-law scaling for EUV brightenings and EUV solar flares, consistent with previously reported X-ray QPPs spanning both solar and stellar flares. The persistence of this scaling over a wide range of energies and scales suggests that QPPs are governed by a common underlying physical mechanism, potentially associated with standing magnetohydrodynamic waves. Distinguishing between candidate wave modes, however, will require further observational and theoretical investigation.