Observations of neutral hydrogen in the corona

Measurements of the linear polarization degree (p) of the emission in the inner corona (< 1.5 R (aS (TM))) in the green and red continuum ranges are discussed. Excess p (Delta p = pgreen - pred), which reaches its maximum at 1.2-1.3 R (aS (TM)) (< 5%) in the polar regions and 20% within large-scale streamers, is present everywhere in the corona. It has been mentioned that excess p can be explained by the presence of neutral hydrogen in the corona.