Markarian 6 nucleus since 1992

We present results of an optical spectral monitoring campaign of the Seyfer t galaxy Markarian 6 for a period of nearly 6 years between 1992 January an d 1997 November carried out with a CCD spectrograph at the 2.6 m Shajn Tele scope of the Crimean Astrophysical Observatory. Our data set consists of 10 4 H beta region spectra and 56 H alpha region spectra. Light curves for H a lpha and H beta emission lines, and the continuum at two bands near these l ines, are given. The continuum variations are generally smooth and very pro nounced. The H beta emission line is found to respond to continuum variatio ns with a time lag of 18 +/- 2 days. The H alpha line has a similar lag. Th e continuum variations at 5170 and 7030 Angstrom are tightly correlated, po inting to no evidence for changes in the nonstellar continuum color in opti cs. A lag of about 5 days between these two continuum bands is suspected. T he blue wing lags behind the red wing, ruling out a radial outflow in the b road-line region (BLR) and, in particular, the biconical outflow as respons ible for the bumps in the broad-line profiles. We find that some changes in the profile shapes of Balmer emission lines in Mrk 6 are related to neithe r the matter redistribution nor the reverberation effects, but probably are driven by the changes in the anisotropy of the ionizing radiation. The H b eta emission-line profile at V-r = +/- 3000 km s(-1) and the optical contin uum show a well-correlated variability (with a lag), while the poor correla tion for the profile segment at V-r = + 1300 km s(-1) can indicate the pres ence of two components in the broad-line profiles. One of the components ha s a double-peaked structure and is associated with the well-known blue bump observed in the Balmer profiles in Mrk 6.