Wavelength dependence of interstellar polarization and ratio of total to selective extinction

A multichannel polarimeter-photometer which uses dichroic filters to separate the (UBVR) spectral regions is described. The instrument was used with a 24-inch rotatable tube telescope for polarimetric observation of nearby stars. Polarization data for 364 nearby stars are tabulated, together with the wavelength dependence of linear and interstellar polarization.