Selection criteria in the distance-longitude diagram. Left: default RW spine model (black line) with nearest-approach longitude range marked in purple. The purple outline marks the part of the RW spine included in the nearest approach longitude range. Filled circles mark the positions of stars in the polarization catalogs we employ, namely the optical P2025 compilation (gray), and the two samples in the NIR from Mimir (red). Only stars with high-significance measurements of distance and polarization are shown. Right: extinction integrated along the latitude axis, from Edenhofer et al. (2024) for pixels within 10° of the default RW spine.