a, The same as in Extended Data Fig. 1b but with superposed fitted flux-rope shape of the CME at 02:39 11 November 2018 ut when the CME had passed halfway through the COR-2A field of view. The CME is very weak and no shock–sheath structure can be identified in these images. The typical aspect of the CME in the image results from the line-of-sight integration of plasma distribution on a bent toroid such that its major axis is located in a plane containing the observing spacecraft (see very similar events in refs. 27,28). b, The position (red) and speed (blue) of the apex of the flux-rope model was derived by iteratively comparing each synthetic image produced by the three-dimensional model with each available COR-2A image. A functional form (arctangent) was imposed for the flux rope’s varying speed. The fitted CME structure assumed here is a bent toroid with an exponential increase of its cross-sectional area from foot point to apex as in ref. 29. The speed was derived by fitting a hyperbolic tangent to the modelled CME position. The speed increases rapidly from under 100 km s−1 at 18:00 10 November 2018 ut to over 350 km s−1 when it exited the COR-2A field of view at around 6:00 ut on 11 November. c, An internal magnetic field structure was expressed analytically inside the envelope of the fitted CME (smooth curves) as in ref. 30, but here keeping a simple circular cross-section of the flux rope. By propagating this flux rope at a constant speed of 380 km s−1 from the time it exits the COR-2 field of view, we predict the CME reaches PSP on 12 November 2018. The predicted arrival time and the magnetic properties of the CME (thick smooth line) are in good agreement with those measured in situ by the FIELDS (magnetic field data; thin lines) and SWEAP instruments (not shown). We therefore conclude that the fitting procedure presented here provides a good description of the evolution of the CME from the upper corona to PSP.