A search for polarization variability in Babcock's star

New linear polarization measurements of the highly magnetic Babcock's star obtained with the Piirola Polarimeter during 18 nights in 1990-1991 confirm the values obtained during 1986-1988 with the Breger polarimeters at the Vienna McDonald Observatories. The excellent agreement rules out long-term polarization variability. A statistical analysis of the new measurements shows no evidence for polarization variability with time scales near the rotation period of nine days over and beyond the expected errors of measurement. No evidence for intrinsic polarization of Babcock's star has been found