GOES 1–8 Å light curve for a flare with quasiperiodic pulsations. (a) Observed soft X-ray flux. (b) Fourier power spectrum (FFT+MCMC). (c) Wavelet power spectrum from the CWT+AR(1) method. (d) Wavelet power spectrum from the CWT+MCMC method. Enhanced power near ∼80 s is visible in the Fourier spectrum, and a localized component at a similar period appears in the time–frequency domain. Black contours indicate the 95% confidence level.