This paper combines data from the three preceding papers in order to analyze the multi-
wave-band variability and spectral energy distribution of the Seyfert I galaxy NGC 4151
during the 1993 December monitoring campaign. The source, which was near its peak
historical brightness, showed strong, correlated variability at X-ray, ultraviolet, and optical
wavelengths; The strongest variatIons were seen in medium-energy (~ 1.5 keV) X-rays, with
a normalized variability amplitude (NVA) of 24%. Weaker (NVA= 6%) variations …

We present the results of an intensive ultraviolet monitoring campaign on the Seyfert 1
galaxy NGC 4151, as part of an effort to study its short-timescale variability over a broad
range in wavelength. The nucleus of NGC 4151 was observed continuously with the
International Ultraviolet Explorer for 9.3 days, yielding a pair of LWP and SWP spectra every-
70 minutes, and during 4 hr periods for 4 days prior to and 5 days after the continuous-
monitoring period. The sampling frequency of the observations is an order of magnitude …