Multiband early optical light curves of EP260321a/SN 26gzf within 30 ks after the start time. The data are from W. Yuan et al. (2026) and T.-W. Chen et al. (2026). The inverted triangles are the upper limits of the flux. The curves are the multiband light curves of the envelope cooling model. The adopted model parameter values are: E_k = 10⁵² erg, M_e = 1.1 M_⊙, R_⋆ = 1R_⊙, Z = 1, f_ρ = 1, and t_X = 2400 s.