Variability in Spectropolarimetric properties of Sy 1.5 galaxy Mrk 6
  Here we present an analysis of spectro-polarimetric observations of type 1.5
AGN Mrk 6, performed with 6m telescope SAO RAN in 12 epochs (2010 -- 2013).
Additionally, the inter-stellar mater (ISM) polarization has been observed and
its contribution to the AGN spectral polarization is taken into account.
  We measured Stokes parameters and determined the polarization parameters in
12 spectra with and without correction for the ISM polarization. We estimated
the time lag between the unpolarized and polarized continuum flux variation of
about ~2 days, that indicates a compact scattering region which contributes to
the polarized continuum variability. The polarization in H{\alpha} is complex,
showing three prominent components in the BLR, one redshifted around +3000 km/s
that corresponds to the red shoulder in H{\alpha}, and two blue-shifted around
-2000 km/s and -6000 km/s.
  We found that the ISM polarization has a very significant influence on the
measured AGN polarization parameters. After correcting the observations for the
ISM polarization we were able to detect the Keplerian motion in the BLR.
  We give a new method for the black hole mass estimation using
spectro-polarimetric observation in the line profile, finding the black hole
mass in Mrk 6 of $M_{BH} \sim 1.53 \cdot 10^8 M_{\odot}$, that is in a good
agreement with reverberation estimates.
