Initial density structure used in heracles for models r1w1, r1w2, r1w3, r1w4, r1w1h, r1w5h, r1w5r, r1w6, and r2w1. Model m15mlt3 (r1) is used for the ejecta of model r1w[1–6][h,r] and model m15mlt1 (r2) for the r2w1, taken at a few hours before shock breakout (Dessart et al. 2013). The atmosphere/wind density is built using a variety of wind mass loss rates and atmospheric scale heights. All models transition to a wind mass loss rate of 10^-6 M_⊙ yr^-1 beyond 2−5 × 10¹⁴ cm (≡ 5−10 R_⋆). (See Sect. 3 and Table 1 for details.)