Data Reduction Induced Errors in the Asteroseismology of Early-Type Stars

In the asteroseismology of early type stars it plays an important role the extremely precise high resolution spectroscopy. Especially the determination of pulsation modes from observations requires the identification of subtle changes in line profiles of a number of chemical elements. As commonly available instruments suitable for this purpose are echelle spectrographs, there is a number of possible imperfections and even systematic errors introduced by the echelle reduction procedures. We will mention several, most critical steps, that should be carefully checked during every reduction.