A time-variable scattered component to broad H alpha in the Seyfert 1 galaxy Mrk 509

We present optical spectropolarimetry data fdr the Seyfert 1 galaxy Mrk 509 for three epochs: 1996 August and 1997 May and August. We confirm previous findings that broad Her has a significantly greater width in the polarized flux spectrum than in total flux, and that the observed polarization is va riable on relatively short time-scales, implying, for scattering, that at l east some of the polarization originates in a compact region. We also find evidence that the observed changes in the degree of polarization (for the c ontinuum and broad wings of Her) and the associated position angle swing (f or the continuum) are similar in pattern to previously observed polarimetry variations. We determine that a multicomponent scattering region is the most likely ori gin for the observed polarization of Mrk 509. The scattering appears to ori ginate from three regions, which we identify with observed or expected comp onents of the active galaxy. The proposed scenario is completely consistent with the unified theory of active galaxies.