Blackbody spectra at maximum (solid line) and minimum (dot-dashed line) temperature over the course of the pulsation for our hypothetical stars with average effective temperature of 10 000, 20 000, 30 000 and 40 000 K (top to bottom). UV-pumping wavelengths for 6 helium-like ions are also shown for reference, C v (red), N vi (yellow), O vii (green), Ne ix (teal), Mg xi (blue) and Si xiii (purple).