Similar to Fig. 5 but for the metal-poor hot subgiant Gaia DR3 4378933739135936000 around its DIB feature. The insert is a zoom onto the flux residual between observed and model spectra around the DIB. It has been renormalised and the DIB characteristics are measured thanks to the Gaussian fit shown in red (EW = 0.0244 nm and central wavelength p₁ = 862.309 nm). The MatisseGauguin atmospheric parameters of this star are T_eff = 6414 K, log(g) = 3.75, [M/H] = −0.61 dex, and [α/Fe] = +0.42 dex (S/N = 293 and CU6 broadening velocity equal to 17.1 km s⁻¹).