Estimated values of the flicker index (α_g) as a function of the white noise level (σ_w) added in the VIRGO time series (red, blue, and green SPM channels, see Fig. 19 of Sulis et al. 2020a). The red star corresponds to the flicker index of the red channel measured at σ_w = σ₃₀ = 30 ppm. Black dots show the flicker indexes inferred from the averaged periodograms of Kepler Sun-like stars. The yellow square shows the flicker index inferred from the averaged periodogram of HD 67458 (CHEOPS), and the yellow star shows its interpolation at σ₃₀.