Left: best-fitting model SED (solid line) consisting of the stellar and present-day wind contribution (dotted line), a detached-shell contribution (dashed line), and an additional black body (dot-dashed line). The wind parameters are the best-fitting parameters of 1 × 10⁻¹⁰ M_⊙ yr⁻¹ for the present-day wind and 3 × 10⁻⁵ M_⊙for the shell mass, derived for 0.1 μm solid sphere amC grains. The best-fitting cool black-body temperature is 5 K. Right: χ-square map for the grid of cool black bodies used to find the best fit. The scaling factor a scales the flux of the black body.