Photometric properties and spatial location of the observed stars. Left panel: K, (J − K) CMD of Liller 1 (gray dots). The likely metal-poor (filled red circles) and metal-rich (filled blue squares) member stars for which we measured chemical abundances (see Sect. 5.2) from the observed X-shooter spectra are indicated. Right panel: distribution of these stars (same symbols) on the plane of the sky with respect to the cluster center, marked with the black cross and located at RA = $263\stackrel{°}{.}3523333$, Dec = $-33\stackrel{°}{.}3895556$. The radii of the dashed black circles are equal to 5, 10, and 15 times the core radius $r_{\mathrm{c}}=5\stackrel{″}{.}39$ (Saracino et al. 2015).