Left: RVs measured using the Na I absorption doublet from Night 1 (blue) and Night 2 (red) folded on a period of 2.915(1) h and plotted with the best RV model (black; K_MD = 189 ± 3 km s⁻¹). This shows that the binary orbital period matches the radio pulse period to within 0.05 percent. Radio pulses (gray) occur just after the maximum redshift of the M dwarf, when it is at the ascending node as viewed from Earth. Right: Trailed spectra (Night 2) of the Na I doublet show good agreement with the RV model (black). Two orbital periods are shown for visual aid.