β Pic spectra around two Fe II lines. Top: zoomed-in view of the 2740 Å Fe II line (E_l = 7955 cm⁻¹), emphasising the two 1997 observations. The December 19 spectrum is close to the stellar spectrum in the [+25; +40] km s⁻¹ range (grey zone), while the December 6 observation shows a clear cometary transit at these radial velocities. Bottom: zoomed-in view of the 2607 Å Fe II line (E_l = 668 cm⁻¹), showing the only two available spectra for this line.