Orbit of SDSS J102915+172927 in the Y vs. X (upper-left), Z vs. X (bottom-left), and Z vs. Y (bottom-right) planes. X, Y, and Z are Galactocentric Cartesian coordinates. Upper-right panel: $\sqrt{}\left(V_R^2+V_Z^2\right)$ vs. V_T (Toomre diagram: Transversal velocity component vs. a combination of the radial and vertical velocity components in Galactocentric cylindrical coordinates). The coloured points are the stars of the good parallax sub-sample of Bonifacio et al. (2021), plotted for reference. They are divided into thin (red) disc, thick (green) disc, and halo (blue) stars, following the Bensby et al. (2014) criteria. The filled star marks SDSS J102915+172927, while the Sun is indicated by the ⊙ symbol.