Onset density (in units of ρ₀) of the d^*(2380) di-baryon (panels a and c) and the Δ⁻ isobar (panels b and d) in β-stable neutron star matter as a function of the dimensionless couplings x_σd^* and x_ωd^*. Panels a and b: UC choice of parameters for the Δ–meson couplings while panels c and d: SC choice. In all cases the nucleonic part is described with the GM1 parametrization of the Glendenning–Moszkowski model. The d^*(2380) noninteracting case is highlighted with squares. The black line corresponds to solutions where the onset density of the d^*(2380) coincides with that of the noninteracting case.