IR observations of the solar corona—a ring around the Sun?

Abstract

The possibility of a permanent ring structure around the Sun was first pointed out by Brecher et al.¹ from evolutionary, physical and chemical considerations as well as constraints arising from observational astronomy related to Sun and its immediate neighbourhood. In particular, Brecher et al.¹ concluded that such a ring, located at ∼4 R_⊙, must consist of refractory particles (graphite, for example) of size >10 km at ∼1,000–2,000 K which, therefore, would emit thermal radiation peaking around 1.5–3.0 µm. We report here our attempt to detect the existence of this ring structure utilizing the IR observations taken during optimal viewing conditions of the total solar eclipse of 16 February 1980.