Polarized source previously not detected by OS23, found using our 3D reconstruction method. Left: polarized intensity map centered on the source. The Stokes I (10, 20, 50) × σ_I noise levels are shown as red contours. Right: magnitude of the LOS profile at the brightest pixel, with the local 8σ_QU level shown as a dashed black line. The shaded area indicates the range of Stokes I leakage between −1 and 1 rad m⁻².