Abstract:
BVRI polarimetry of AC Her shows that the wavelength dependence of polarization is weak with a marginal increase towards blue and that the position angle is nearly independent of wavelength. It is argued that the interstellar component of polarization in the direction of AC Her is negligile (less than 0.1 percent). The polarization observed in AC Her most probably results from a combination of pulsation related asymmetry in the star and circumstellar grain scattering; and its variation during a light cycle is not caused by changes in the circumstellar dust envelope but rather by the changes in asymmetry in the star
