Left upper panel: 2MASS K_s-band image of the observed region GLIMPSE9Large in Table 1. The enclosed NICMOS (′′) fields studied by Messineo et al. (2010) are shown as squares; the central NICMOS field covers the stellar cluster GLIMPSE9. Two dashed circles indicate the circle and annular regions used for the CMDs. Upper right panel: HST/NICMOS H − K_s vs. K_s diagram of the GLIMPSE9 cluster (Messineo et al. 2010). Left lower panel: UKIDSS-2MASS K_s versus J − K_s diagram of the GLIMPSE9 cluster (2MASS data are used above K_s ≈ 10.5 mag). Right lower panel: UKIDSS-2MASS K_s versus J − K_s diagram of a region surrounding the GLIMPSE9 cluster. Spectroscopically observed stars are marked as summarized in the legend. Of stars are marked with asterisks, late-O and early-B types with filled circles, RSGs and cRSGs with triangles. Labels 903, 904, 905 indicate massive stars [MFD2010]3, [MFD2010]4, and [MFD2010]5 from Messineo et al. (2010).