Left: high resolution spectrum of J0053, the star at the center of the SN 1181 remnant. Saturated interstellar absorption lines of Na I are consistent with the significant dust extinction in the direction of J0053. High-velocity Na I absorption is detected at −61.0 ± 0.2 km s⁻¹ in both Na I components. Right: close-up of the D₂ component (solid red line) plotted versus heliocentric velocity. The K I absorption feature is shown as a light purple line. The high-velocity component is below the K I detection limit. The solid orange band indicates the systemic velocity of the nebula’s [S II] emission assuming that it is expanding symmetrically.