Coronal polarization from solar eclipse observations

Measurements of white-light corona polarization, performed during three solar eclipses, are presented. Corresponding maps of polarization reflect the actual coronal structures far better than isophotes do. Analysis of the degree of polarization also allows us to say more about the density distribution along the line of sight. Unique green-line corona eclipse images were obtained on July 11, 1991. The distribution of polarization around the Sun is shown. We have found a reversed dependence (anticorrelation) between the degree of polarization and the green-line intensity. Polarization data contains new information about the relative role of electron collisions and photospheric radiation in the excitation of the Fe XIV 530.3 nm emission line. Eliminating the dependence of polarization on distance, the anticorrelation found distinctly splits into two branches. Different types of coronal structures are identified in the anticorrelation diagram.