Evidence for the frequency dependence of ﹩{Q}_{\star }^{{\prime} }﹩. Shown are the values of ﹩{Q}_{\star }^{{\prime} }﹩ inferred for each system, as a function of the tidal forcing period. Black points are cases for which ﹩{Q}_{\star }^{{\prime} }﹩ was bounded to within two orders of magnitude. Thinner gray symbols are cases for which the two-sided limits span more than two orders of magnitude. Gray arrows indicate lower limits. The blue curve is a saturated power-law fit to the points with two-sided limits (Equation (2)).