VLT/FORS2 spectropolarimetry of NGC 1566. Top panel: Total flux spectrum (in 10⁻¹⁶ erg s⁻¹ cm⁻² Å⁻¹). The most prominent telluric absorption lines are indicated in purple, the calcium triplet absorption lines resulting from host starlight are indicated in red, and the most prominent emission lines are labeled in black. The 300I spectrum has been offset to match the 300V spectrum by applying a correction factor of 0.86 to account for the different observing conditions and grisms. Second panel: Polarized flux; that is, the multiplication of the total flux with the polarization degree, P. Third panel: Linear polarization degree, P. Bottom panel: Polarization position angle, θ. Spectra are shown at native spectral resolution (no binning). Observational errors are indicated in transparent gray for each spectral bin.