Optical Continuum and Emission-Line Variability of the
Seyfert 1 Galaxy Markarian 509
Carone, T.E., et al., 1996, ApJ, 471, 737
We report on the results of a five-year coordinated program of spectroscopic monitoring of the luminous Seyfert 1 galaxy Markarian 509. The Hbeta and He II (lambda)4686 emission lines are found to respond to continuum variations with time lags of ~80 and ~60 days, respectively, considerably longer than the emission-line lags measured for other Seyfert galaxies.