Latest results on the period behaviour of the contact binary AB And

Abstract

The O−C diagram of the contact eclipsing binary AB And was reanalysed, using data obtained up to now. It was thus found that the real period variations, presented by the P(E)−P e function, have changed; both P mod and its amplitude continue to decrease. Moreover, assuming that the observed orbital period changes of AB And are due only to magnetic activity, the variation in the magnetic field and also P mod were calculated. As their variability was found to be less than that of other examined cases, this is connected to the O−C diagram shape of AB And.