NEARLY SIMULTANEOUS VERY LONG-BASE-LINE INTERFEROMETRY AND OPTICAL POLARIMETRY OF BLAZARS

One of the most promising approaches to unraveling the relationship be tween the optical and radio emission in AGN is to obtain nearly simult aneous optical polarization and VLBI polarization data. We have obtain ed such data for five blazars (0735 + 178, OJ 287, 1219 + 285, 3C 279, and BL Lac) during a number of lambda = 6 cm VLBI polarization runs. In each of these five sources, we find evidence for a correlation betw een the optical polarization position angle and the radio polarization position angle in either the VLBI core or the VLBI jet, usually in th e VLBI core. Such results indicate that the optical and radio polarize d emission are linked to a much greater extent than has usually been e xpected and are most likely cospatial. Preliminary evidence suggests t hat frequently the optical polarization is associated with the emergen ce of new VLBI components.