Polarization vectors overplotted on the WISE 12 μm image of BRC 17 (left panel) and BRC 18 (right panel) of our optical data (white) and of the Planck data (red). The binned polarization vectors along Galactic longitude bins are shown in both panels for our data (thick white) and Planck (thick red). The length of the vectors corresponds to the degree of polarization, and the orientation corresponds to the position angle measured from the north and increasing toward the east. The vectors corresponding to a polarization of 2% are shown for reference in their respective colors.