POLARIZATION OF THE GREEN-LINE CORONA ON JULY 11, 1991 SOLAR ECLIPSE

High quality photographic polarized images of the green-line lambda 53 0.3 nm corona were obtained during the July 11, 1991 solar eclipse by using a narrow-band 0.17 nm interference filter. Image processing allo wed us to derive the green-line polarization within the range 1.08 - 1 .40 R.. The corresponding degrees of polarization p vary from 0% up to about 30% in different coronal regions. At equatorial latitudes p var ies from 0% to 15%, while in the brightest coronal regions it does not exceed 5%. In regions of observed high-latitude white-light coronal s treamers, the green-line polarization gradually increases with distanc e from 10% to about 30%. Anticorrelation between the degree of polariz ation and the green-line corona intensity was found in analysing the e ntire data matrix. It seems that this finding in itself contains infor mation about the role of electron collisions in the excitation of the green line, and about certain physical properties of the coronal magne tic field.