Color−magnitude diagram (CMD) of the open cluster NGC 2264 in the Johnson B and V filters (gray points, source: WEBDA database of open clusters; Mermilliod & Paunzen 2003): top panel – complete cluster CMD where the eleven stars are marked as black symbols; bottom panel – zoom into the most luminous part of the CMD where the pulsators are marked with blue downwards triangles, stars showing rotational modulation are identified as black upward triangles, the Be star is shown as a green square and the binary is given as a red diamond. Numbers are according to the identification in Table 1.