Heliocentric velocities versus Fe4383 index for all 28 valid spectra. Smoothed histograms show the distribution of the two parameters. We also show the velocities distribution from the Besançon model. Member stars are located in the lower right quadrant indicated by the dashed lines. Sequence 1 (S1), sequence 2 (S2), and peculiar stars (pec.) defined in Fig. 5 are indicated by blue squares, orange diamonds, and green crosses, respectively. CN-strong (δS(3839) ≥ 0) and CN-weak stars (δS(3839) < 0) are represented by filled and open symbols, respectively. These symbols and colours are used also in the following figures. Dashed lines are set by eye at the lower limit of v_helio and the upper limit of Fe4383 distributions.