INTEGRATED LUMINOSITY DISTRIBUTION OF GALACTIC OPEN CLUSTERS

The integrated magnitudes of 221 Galactic open clusters have been used to derive the luminosity function. The completeness of the data has also been discussed. In the luminosity distribution the maximum frequency of clusters occurs near I(M(v)) = -3.m5, and some plausible reasons for a sharp cut-off at I(M(v)) = -2.m0 have been discussed. It is concluded that the paucity of the clusters fainter than I(M(v)) = -2.m0 is not purely due to selection effects. The surface density of the clusters for different magnitude intervals has been obtained using the completeness radius estimated from the log N-log d plots. A relation between I(M(v)) and surface density has been obtained which yields a steeper slope than that obtained by van den Bergh & Lafontaine (1984).