Published online by Cambridge University Press: 12 April 2016
The examination of high resolution spectra of two Ap stars, HD 965 and HD 217522, discloses a spectral appearance similar to Przybylski’s star. Here we present the preliminary results of a comparative study of all three stars. Further, we discuss the possibility of having a good spectroscopic indicator of magnetic fields in Ap stars. In all three studied stars the strong Lu II line at λ 5984 Å is present and very likely not affected by significant blends. Its hyperfine structure has been recently measured and we show the results of a model that accounts for the Paschen-Back effect on hyperfine structure.