(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.