OPTICAL POLARIZATION STUDY TOWARDS THE OPEN CLUSTER NGC 62491

We present multicolor linear polarimetric data (UBVRI) of 30 of the brightest stars in the region of the open cluster NGC 6249. The cluster members were found to be part of two subgroups with average polarization and orientation of the electric vector of P-V = 1.7% +/- 0.13, theta(V) = 39.7 degrees +/- 2.2; and P-V = 2.34% +/- 0.07, theta(V) = 41.0 degrees +/- 1.2, respectively. This difference in polarization may be a consequence of the presence of a dark, U-shaped absorbing zone seen on the central region, and probably located in front of, or inside, the cluster. From the study of the evolution of the A(upsilon), with the distance,we found evidence of the existence of two layers of dust at distances of approximate to 250 pc and approximate to 600 pc. The comparison between the polarimetric parameters of NGC 6249 and those of the nearby cluster NGC 6250 showed some coincidences.