Periods (top panel) and associated pulsation amplitudes (bottom panel) of the periodic variables brighter than V′ = 15.5 mag, as a function of their V′ magnitude. Multiple periods of the same object are connected with solid lines (note that the period separations of multiperiodic variables are often much smaller than the periods themselves, resulting in the vertical solid lines being reduced to a black point inside the markers in the top panel). The color of each point indicates the S/N of the peak in the periodogram corresponding to the given frequency, according to the color scale displayed on the right of the figure. When overlapping, the marker of the highest S/N appears in the plot.