Continuum-subtracted flux spectrum (grey) of AT 2023mhs focussing on the Hα and Hβ, which were fitted with an asymmetric Gaussian function (dashed black lines). The polarisation degree is shown in red. In the upper-left corners, the ratio of the widths σ₁ (blue wing) and σ₂ (red wing) of the asymmetric Gaussian fit to each line are shown. A ratio σ₂/σ₁ > 1 for both lines indicates they are asymmetric with more broadened red wings.