Results of the period analysis for the SAT 97/98 y-band data set. Panel A: 404 y out-of-eclipse photometry showing magnitude vs. time where the primary and secondary eclipses have been removed. The horizontal line is the mean flux out of the eclipses as determined by PERIOD04 and was subtracted prior to the computation of the Fourier spectrum. Panel B: power spectrum and 1, 2, and 3σ noise levels. A frequency at f₁ = 0.2138 c/d is detected corresponding to a period of 4.68 days. Frequencies near 1 c/d are likely daily/nightly alias frequencies. Panel C: power spectrum of the spectral (data gap structure) window. Panel D: power spectrum after removing the f₁ frequency component with the highest power. Panels B and D have the same scale along the y-axis.