Linear Polarization Towards Galactic Anticenter direction: the Case of Alessi 1

Abstract

We present linear polarization towards the direction of the star cluster Alessi 1, which is located in the anti-galactic centre direction. We have observed the cluster using ARIES IMaging POLarimeter (AIMPOL) as a back-end instrument at 104-cm Sampuranand telescope, ARIES, Nainital. The average degree of polarization towards the cluster Alessi 1 are found to be 0.80±0.38 %, 0.80±0.23 %, 0.81±0.26 %, 0.86±0.32 %, in B, V, R, and I photometric bands, respectively, whereas the position angles are found to be 86±11o, 81±10o, 78±8o, 85±8o in B, V, R, and I bands, respectively. Polarization towards Alessi 1 cluster is dominated by foreground dust grains and probably a single layer of the polarized source appears to exist at ~ 0.7 kpc close to Alessi 1 cluster. The minor axis of dust grains towards the cluster Alessi 1 appears aligned along the galactic magnetic field.