Time-delay estimation from the dispersion technique. The dispersion spectra D₄² are based on a Gaussian weighting function whose width is described by the parameter β, as well as a fifth-degree microlensing polynomial (N_ml = 5; see main text). Top panel: D₄² spectra using the NOT light curves plus the new GLENDAMA+ brightness records and five values of β. These spectra have minima at time lags τ = 13–15 d. Bottom panel: 1σ confidence intervals for the time delay using 1000 synthetic light curves of each image and a large set of β values. A combined measurement from the six delay intervals for β = 4–9 d is highlighted with a light grey rectangle encompassing the individual measurements.