The visible spectrum of the lower corona during the total eclipse of May 30, 1965

Spectra obtained during the May 30, 1965 eclipse by Dunn aboard the NASA aircraft are presented and analyzed. Equivalent widths and absolute intensities are given for 39 coronal lines between 3300 and 8200 Å around the west limb of the Sun at two heights. Details are given on the reduction process, and comparisons are made with other observations from the same eclipse. Some line identifications are discussed.     

Absolute abundances and distribution of material versus density and temperature in a coronal condensation

Data derived from coronal eclipse spectra in the visible range are analyzed in terms of electron density and temperature in a coronal condensation using the method recently developed by Jefferies, Orrall and Zirker. A mean density and a certain amount of material are associated to each temperature. Abundances relative to Fe are derived for Ni, Cr, Mn, S, Ca. The absolute abundance of Fe is found to be 2 × 10^?5. No absolute calibration is required. It appears that there must exist a non-negligible amount of ‘cold’ material (T _e < 10⁶K) in the corona, which cannot be observed in the visible spectral range.

     

On the identification of Fe ix and Ni xi lines from coronal spectral

Identifications of coronal lines with transitions of Fe ix and Ni xi, as proposed by Wagner and House, and Svensson, Ekberg and Edlén, are checked by means of line intensity ratios, from observations obtained at the 1965 eclipse. All the suggestions of Svensson, Ekberg and Edlén are suitable.