Inference result for V1878 Ori. Top: fit to the observed spectral lines (black histograms) with the spectra corresponding to the best-fitting parameters (solid red line). The dashed blue lines correspond to theoretical spectra without accounting for the magnetic field. Central wavelengths in Å of each line are given above the corresponding panels. Bottom: posterior distribution of the average surface magnetic field strength in the components of V1878 Ori. The vertical lines show the median (solid line) value and 68% percentile (dashed lines).