Top: individual spectrum (black) for the circled target in Fig. 1 and the green data point in Fig. 4. The green lines show the telluric model before and after convolution. Gray rectangles indicate masks at strong sky emission lines (blue). Bottom: example of fit is shown. The blue curve is the convolved stellar model. The magenta curve is the fitted stellar+telluric model. The dashed orange line shows the DIB position.