B relative to set A are $\varphi = 0.982 \pm 0.048$ and $G = (-1.243 \pm 0.729) \times 10^{-15}$. Both the  and 686 fluxes are adjusted as in eq. (\[eq:defphi\]); the fact that the factor $\varphi$ is so close to unity indicates that most of the NLR in this galaxy arises within a few arcseconds of the nucleus.

The final continuum $F_{\lambda}$(5100Å) and   emission-line fluxes are given in Table 2. Simultaneous (to within 0.1 day) measurements were averaged, weighted by the reciprocal of their variances.

Analysis
========

Continuum Variability
---------------------

The light curves listed in Table 2 are plotted in Fig. 1, along with contemporaneous 2–10keV X-ray light curves. The data shown here span three observing seasons, beginning in 1996 January and ending in 1998 July. A summary of the general variability characteristics is given in Table 3. For the complete data base and for individual subsets of the data as given in column (1), columns (2) – (4) give respectively the number of individual observations and the average and median time intervals between them. The mean flux is given in column (5), and columns (6) and (7) give two widely used measures of the variability, , the root-mean-square (rms) 