Left panel: distribution of Ba and Y abundances when measured for both elements. The elements behave close to a 1:1 correlation indicated by a dashed black line in the background. For higher abundances however, Ba is slightly more abundant than Y. Right panel: observation (black) and synthesis (red) of Ba and Y lines of the s-process enhanced 2MASS J20120895-4129341 (indicated by a red dot in the left panel).