Some considerations concerning the Zeeman effect in magnetic stars

A detailed analysis of the multiplet structure of lines used for observations of stellar magnetic fields is presented. It is shown that LS-coupling does not hold good for many of the spectroscopic terms of Ti II and Cr II and that the magnetic fields observed in several magnetic stars are strong enough to produce transition to the Paschen-Back effect in some of these lines. In order to avoid possible erroneous results it is recommended that only lines originating from Russell-Saunders terms be used for magnetic observations. A list of Ti II, Cr II and Fe I lines is given which should not be used in measuring strong magnetic fields in magnetic stars. (Auth.)