Left panel: J − H versus H − K diagram. The filled circles represent sources located within a radius of 15.5″, the formal limits of the embedded cluster. The open circles represent sources that lie outside this circle. The solid line marks the loci of the main-sequence (MS) stars from Koornneef (1983), while the dashed lines define the reddening band extending from the MS using the reddening vector from Rieke & Lebofsky (1985). Right panel: H − K vs. K −  [3.6]  diagram for the sources that could also be measured on the IRAC [3.6] images. Symbols are as in the left panel. In both, the reddening vector (broken line) is from Tapia (1981) and the loci of the MS (solid line), from Koornneef (1983); the crosses near the lower right corners show the mean statistical error of the individual measurements.