From left to right: grayscale representation of the CLEANed periodograms as a function of velocity in the stellar rest frame around the Si iv λ1394 line for the IUE datasets of October 1989, 1991, and 1994. The profiles of the 1994 data are shown in Fig. 1. The legend bars give the corresponding grayscale codings. The horizontal dashed line and tickmark at ν₂ = 0.245 d^-1 indicate our adopted rotation frequency of the star. The three side panels display the total power over the velocity range of the main panel in the same units. The vertical dashed line indicates the estimated noise level in the power (see text). The tickmark at ν₀ = 0.403 d^-1 (2.48 d) shows the dominant frequency in the 1989 data.