Radial density profile in the region of Trumpler 27, upper left panel. Bars are Poisson errors. The (J − H),(H − K) color–color diagram of all stars in the region is shown in the upper right panel. White and red squares are stars in Tables 2 and 3, respectively. The cross indicates the average color errors. Large blue squares give the position of the YSO candidates, and the arrow points out the position of the star N. 1796 outside the diagram limits. Solid black line is the intrinsic relation from Koornneef (1983); the two gray dashed lines are color excesses relations for A_V = 6 mag for early- and late-type stars. The lower left and right panels show the K,(J − K) and V,(J − K) color–magnitude diagrams. Symbols as in the upper right panel.