Inferred current Galactic rest frame velocity, v_grf(t = t₀), and ejection velocity, v_tr(t = t_SN), of US 708, as dictated by observed radial velocity and proper motion, correlated with the ejection velocity spectra, v_ej(t = t_SN), with a WD explosion mass (M_WD(t = t_SN)) as labeled. Observed space and ejection velocities are base either on Geier et al. (2015) (denoted by subscript “2015”) or on proper motions according to Gaia DR2 (subscript “2020”, Gaia Collaboration 2018) Spectra are represented by the envelopes of their depictions in Fig. 8 for legibility. The current space and inferred ejection velocities, as determined by Geier et al. (2015) are depicted as purple dots.