SCYON Abstract

Received on April 30 2008

Optical polarimetric study of open clusters: Distribution of Interstellar matter towards NGC 654

AuthorsBiman J. Medhi (1), Maheswar. G (1,2) , J.C. Pandey (1), T.S. Kumar (1), and Ram Sagar (1)
Affiliation(1) Aryabhatta Research Institute of Observational Sciences, Manora Peak, Nainital - 263 129, India
(2) Korea Astronomy and Space Science Institute 61-1, Hwaam-dong, Yuseong-gu, Daejeon, Republic of Korea 305-348
Accepted byMonthly Notices of the Royal Astronomical Society
Links NGC 654


We present new B, V and R linear polarimetric observations for 61 stars towards the region of the young open cluster NGC 654. In this study we found evidence for the presence of at least two layers of dust along the line of sight to the cluster. The distances to the two dust layers are estimated to be ~ 200 pc and ~ 1 kpc which are located much closer to the Sun than the cluster (~ 2.4 kpc). Both the dust layers have their local magnetic field orientation nearly parallel to the direction of the Galactic plane. The foreground dust layer is found to have a ring morphology with the central hole coinciding with the center of the cluster. The foreground dust grains are suggested to be mainly responsible for both the observed differential reddening and the polarization towards the cluster.