A NEAR-INFRARED PHOTOMETRIC-STUDY OF THE YOUNG ORION NEBULA STAR CLUSTER NGC-1976

We have measured the JHK magnitudes of 47 stars in the region of the e xtremely young Orion nebula star cluster NGC 1976. These, in combinati on with the existing near-infrared and optical data, are used to study the intracluster extinction law. This indicates an anomalous distribu tion of intracluster grains in the vicinity of many stars causing less extinction in the U, B, R and I passbands than that obtained from the colour excess E(V-J) using a normal interstellar extinction law. This implies a small shift in the grain size distribution towards larger t han normal sized particles in these regions.