Hess diagram of JP×G^r16.5_5kpc sample for a) J0378 – J0861 and b) u – i. Panel c) shows the distribution of stars in the (r vs z_GC) plane. The stellar colours and magnitudes are corrected by the effect of dust (Green et al. 2018; Schlafly & Finkbeiner 2011). The horizontal dotted line indicates the absolute r magnitude equal to 4.2 mag, separating the regions we used to extract the information of ages and metallicities. The arrow illustrates the dimming and reddening vector corresponding to A_V = 1 mag. The crosses arranged vertically show the colour and magnitude average errors, computed for all star within interval of size ∆r = 1 mag.