ASPs computed iteratively on the solar data. Left column: ASPs corresponding to Eq. (7) for different values of τ. Middle column: zoomed-in view of the maximum peak of the ASP. Right: statistical test on the timescale described in Sect. 2.1.3. On the x axis we represent the ratio of τ to the total observation time assumed to be true. For each τ_i, i = 1…4 in abscissa, the position of the markers corresponding to τ_j, j = 1…4 is represented as the value of the periodogram peak for τ_i minus the expectancy of , and the error bar is the square root of the variance of D_z. Informally, the markers represent what the periodogram values at τ_j should be if τ_i in abscissa were the true timescale.