On the rotation of the chemically peculiar magnetic star 56 Arietis

¹ Department of Physics, The Citadel, 171 Moultrie Street, Charleston, SC 29409, USA
² Crimean Astrophysical Observatory, 334413 Nauchny, Crimea, Ukraine e-mail: victor@crao.crimea.ua; savanov@crao.crimea.ua
³ Isaac Newton Institute of Chile, Crimean Branch, Ukraine
⁴ Institute of Astronomy, Russian Academy of Sciences, Pyatnitskaya 48, 109017 Moscow, Russia e-mail: ryabchik@inasan.rssi.ru
⁵ Institute of Astronomy, University of Vienna, Türkenschanzstr. 17, 1180 Vienna, Austria

Corresponding author: Saul J. Adelman, adelmans@adelvx.citadel.edu

Received: 25 April 2001
Accepted: 20 June 2001

Abstract

This study used extensive sets of phase resolved photometric and spectroscopic data obtained by the authors and supplemented by that from the literature 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.