Best-fitting atmospheric model for ZTF J2252−05, computed with the hydrogen-deficient code of Koester (2010) and using the parameters listed in Table 3. The bright spot contribution is included as an additional constant term in F_λ; it accounts for about 16% of the total flux. The model includes Si, N, Al, and Fe. Geocoronal lines, ISM-contaminated regions, potential disc emission, and possible veiling absorption are masked. The residuals are shown below the spectrum.