ارتباط میدان مغناطیسی غیر یکنواخت و تغییرات دوره مداری سیستم‌های دوتایی نزدیک

 Magnetic activity of one or both components of close binary systems can cause orbital period variation of the systems.Variation in gravitational quadropole moment will change the orbital period of the systems. In this article, we suppose that magnetic field is poloidal-troidal according to dynamo theory, and finds its relation with period change in the systems.