Residuals ΔV _R for the stars in CU6GB-cal as a function of . The overall median value is −0.01 km s⁻¹ and the dispersion is 0.20 km s⁻¹ (Table 4). The magnitude distribution of the CU6BG-cal stars is shown in Fig. 3. The stars with ≤ 9 are used as standard stars in the wavelength calibration. The pipeline processes stars with ≤ 12. There is nobright-end limit in the selection of the stars to process, but the pipeline removes the saturated spectra (Sect. 6.1.1).