Power spectra of the flux spectra of U Hya and V Hya plotted against the square of the frequency. The top and bottom panels are for orders 80 (7030–7160 Å) and 84 (6700– 6800 Å), respectively. Left panels: unbroadened spectra of U Hya. Right panels: rotationally broadened spectra of U Hya with the noise of the original power spectrum added. Power spectra are normalized at 0.5 cycles Å⁻¹.