Fr.: raie transaurorale
A forbidden line emitted by interstellar ionized gas by several atomic species (O, O+, O++, N+, S++, etc.) corresponding to the transition from the electronic state 1S to 3P. Examples are the ultraviolet line of the doubly ionized oxygen [O III] at 2321 A and [N II] 3063 A. → auroral line; → forbidden line; → nebular line.