On the rotation of the chemically peculiar magnetic star 56 Arietis

This study used extensive sets of phase resolved photometric and spectrosco pic data obtained by the authors and supplemented by that from the literatu re to investigate the light and equivalent width variations of the mCP star 56 Ari. Its rotational period is found to be increasing at a rate of about 2 s per 100 years. In addition there is evidence for a second period whose length is about 5 years which is attributed to the precession of the axis of rotation.