Plane-of-sky magnetic-field orientations inferred from optical stellar polarimetry (red segments) and Planck 353 GHz dust-emission polarization (green lines), overlaid on the H I absorption map. Each stellar segment corresponds to the average Stokes parameters within ﹩1{0}^{{\prime} }\times 1{0}^{{\prime} }﹩ spatial cells (see the text). The close agreement between the two tracers demonstrates that starlight and dust emission probe the same large-scale magnetic-field geometry across the R–C cloud. The segment scale for the optical polarimetry is provided in the lower-left corner.