Wavelength dependence of polarization. XIII. Interstellar extinction and polarization correlations.

Observations of the wavelength dependence of polarixation and UB VRI photometry of highly polarixed stars were made. Two extreme cases of the wavelength dependence of the interstellar polarization were found: the maximum polarization of stars HD 147889 and 204827 is observed at 0.8 and 0.4M, respectively. The variations of interstellar extinction in the infrared are correlated with the wavelength of maximum polariza- tion. Van de Hulst's theory of light scattering by infinite cylinders is used to explain the correlations.