SED of Warhol arc (black curve, from Palencia et al. 2025). The best fit (red curve) corresponds to a single star burst model at an age of ∼350 Myr with Z_★ = 0.32 ± 0.12 Z_⊙ and A_V = 0.91 ± 0.04. This model predicts B/R = 10⁻⁷, orders of magnitude from the observed B/R = 0.33 ± 0.26. Among all the models that can reproduce the observed B/R ratio well, we show the best fit SED as a blue curve. This model corresponds to a single star burst at an age of ∼80 Myr with Z_★ = 0.8 ± 0.4 Z_⊙, and A_V = 0.5 ± 0.3. We adopted a Kroupa IMF in both models.