Further Polarization Studies of Grw+70°8247 and Other White Dwarfs

Further observations of polarization in the white dwarf Grw+7008247 have been made. The circular polarization in a broad band from 4000 to 6000 A is found not to fluctuate by more than 3 percent on a time scale from 24 seconds to a few days. The circular polarization rises steeply from less than 1 percent at 3300 A to 3.5 percent at 4000 A, and then drops slowly to 2.5 percent at 7600 A. In ultraviolet and blue light the shows a component of linear polarization of between 2 and 3.5 percent at a position angle of about 20 Six other DC white dwarfs, one DA and one DBp, examined for circular polarization, gave null results generally to an accuracy of about 0.1 percent.