R CrB in the brightness minimum of 1988/1989

URVRI photometry and polarimetry of R CrB in the deep minimum of 1988/1989 of 1988/1989 (δV=5m4) revealed some new peculiarities: 1)the polarization maximum occured a month after the blueing maximum; 2)there was a strong correlation between V and the colour V-I; 3)the loopshape track of polarization vector on the Stokes parameters diagram was found with a counter-clockwise run of dots, indicating the rotation of the scattering plane during the minimum; 4)the preferential plane of polarization is about 90 deg in the equatorial frame of coordinates; it is quite different from the previously observed polarization angles. The comparison of the polarization angles at the time of 8 minima leads to the conclusion that no preferred plane exists for R CrB