Attention is given to the discovery of two narrow variable lines (L1 and L2) in the ultraviolet spectrum of NGC 4151. Li and L2 have a full width at half maximum of less than 7 and 16 A respectively, and vary in intensity by a factor of 3 in less than 10 days; they appear on either side of the C IV 1550 A line at lambda (rest) = 1518.5 and 1594.4 A. It is suggested that the regions emitting L1 and L2 are associated with a two-sided jet reminiscent of SS 433.
Ulrich M., H., Altamore, A., Boksenberg, A., Bromage G., E., Clavel, J. (1986). Discovery of narrow and variable lines in the ultraviolet spectrum of the Seyfert galaxy NGC 4151, and an outline of our previous results. In Structure and evolution of active galactic nuclei; Proceedings of the International Meeting, Trieste, Italy, April 10-13, 1985 (pp.275-296). Dordrecht, D. Reidel Publishing Co..