(1945) The identification of the coronal lines. Mon.
Grotrian (famous for the so-called Grotrian diagrams of atomic energy levels) noticed (3) a possible transition whose wavelength matches the red coronal line (637.4 nm).
Electron capture is thus associated with the activation of a highly ionized species which then emits the well known
coronal lines. Unlike the SSM, light need not be invoked to excite these highly ionized species.
22, as both chromospheric lines (see [section]3.4, [section]3.5, [section]3.6) and
coronal lines (see [section]3.8) can be detected within coronal loops.