Panels A: sketch of the blunt (A1) and oblong (A2) shape of the heliopause. Panels B: magnetic field lines and magnitudes of the magnetic field in the plane determined by V_LISM and B_LISM vectors. Panel B1: a model with the magnetic field critical point above Voyager 1 (Model 1 hereafter); panel B2: a model with the magnetic field critical point (B = 0) below Voyager 2; panel B3: a model with the critical point located in between Voyager 1 and 2 (B3). Panels C: projections of magnetic field lines on the heliopause. Panels C1–C3: same models as panels B1, B2 and B3, respectively.