A

David

Darling

coronal lines

Coronal lines are strong emission lines in the spectrum of the Sun's corona caused by very high excitation metal ions, especially those of iron. The strongest of all is the green coronal green line [Fe XIV] (due to the Fe13+ ion) at 5303 Å. Other prominent ones are [FeX] at 6375 Å and [FeXI] at 7892 Å.