Graphical representation of the population that was chemodynamically associated with the CN-strong star Gaia DR2 2507434583516170240 (Sgr CNs 3). The color coding and circle sizes have the same meaning as in Fig. 7. Additional red stars indicate the identified RR Lyrae variables (see main text). Left panel: position on the sky on top of rejected stars from the SDSS footprint (gray dots). Middle panel: photometric associations in the Gaia CMD. To guide the eye, isochrones that represent ages from 4 to 13 Gyr (white to dark blue) at the mean [Fe/H] of the population are shown for reference. The CN-strong star is labeled “CN“. Right panel: RR Lyrae G magnitudes and their inferred distances (red stars) in comparison to the spectrophotometric distance of the CN-strong star (black circle, see Sect. 3.2).