The model of the phenomenon responsible for variations of polarization and brightness of MU Cep.

A theoretical model based on the 'star-dust' hypothesis of Hemenway et al. (1972) is used to explain variations in intrinsic light polarization of the star mu Cep. According to the model, polarization occurs when light is scattered by streams of dust grains ejected from two active antipodal regions of mu Cep, and is directed along magnetic field lines from the polar regions. Estimates of the degree of intrinsic light polarization over a period of several years were derived from the following parameters: mass loss rate, dust grain size, and the number of grains ejected from mu Cep. It is shown that the model estimates of polarization did not exceed known limits. Predictions of the variation of light and polarization were obtained on the basis of the theoretical calculations, and the results are compared with observations of mu Cep carried out from June 1981 to June 1983.