The spectral energy distribution of stars above the ZAMS in the central part of the open cluster NGC 6383.

The stars in the central part of the very young open cluster NGC 6383, as delineated by FitzGerald et al. (1978), have been observed in the Walraven photometric system. From these observations it is found that the reddening toward the central region, due to foreground interstellar matter, is uniform and amounts to E(V - B) = 0.120 + or - 0.003 (equivalent to E(B V)j = 0.30 + or - 0.01 m in the Johnson system). The distance, derived with this color excess, is 1.4 + or - 0.15 kpc. A number of stars located above the ZAMS were observed spectroscopically and photometrically in the red and near-infrared for the study of their spectral energy distribution. The most interesting result is that three of them were found to have excess infrared radiation most probably due to thermal emission of circumstellar dust grains, indicating that they are pre-main sequence objects. The results of a study of the circumstellar dust shells of two of these stars are presented.