Resulting background fit done with Diamonds  (red curve) for the star KIC 4937056 in the cluster NGC 6819 overlaid on the original PSD of the star (in gray) and its smoothed version (black curve) using a boxcar with a width set to Δν/ 5, where Δν is computed using the Δν − ν_max relation for RGs calibrated by Huber et al. (2011). The different components that constitute B(ν) (Eq. (4)) and G(ν) (Eq. (5)) are indicated with dot-dashed blue lines, while the noise term N(ν) (Eq. (3)) is shown with a dot-dashed yellow curve. The dotted green curve shows the overall fit of the background when the Gaussian envelope is included. Median values of the free parameters for each background component are used, as listed in Table B.2. Top panel: the meso-granulation component (a_meso,b_meso) appears as a kink at ~ 10 μHz  (arrow) and its amplitude squared () is represented by the area of the shaded blue region. Bottom panel: same as the top panel but showing the parameters of the granulation component (a_gran, b_gran).