3D PIC simulation Fit to HD 189733b C II 133.5 nm light curve. The simulations are obtained for the stellar plasma parameters indicated in Table 4. A solar C/H = 2.45 × 10^-4 is assumed (Asplund et al. 2005). (Dashed) Model assuming a magnetic field strength of 7 G for the exoplanet and a fast stellar wind (speed ~ 500 km s^-1, density ~6 × 10⁶  cm^-3, and temperature ~4 × 10⁶ K). (Solid) Using a magnetic field strength of ~5.3 G for HD 189733b, and stellar wind speed of ~250 km s^-1, temperature ~1.2 × 10⁵ K, and density ~6.3 × 10⁶ cm^-3 lead to a better fit corresponding to a MP position of ~16.7 R_p  upstream. This solution is not unique (see text).