Motion of J1036 B and C centre of mass in the reference frame of J1036 A. Upper plot: full estimated period of the centre of mass between B and C around A for our fit using no mass constraints (dashed), our dynamical mass of the system as M_est,dyn = 1.0 ± 0.3 M_⊙ (solid), and the photometric mass estimate of the system as M_est,phot = 0.65 ± 0.2 M_⊙. Lower plot: same as the above but zoomed in on the observed data points where the ellipsis depicts the errors of the B (green) and C (blue) component positions. The brown lines connect B and C to the computed centre of mass. Only ≈35° of the full orbit has been covered and thus may not be well represented here.