Markarian 110 is a nearby (z=0.0355) Seyfert 1 galaxy with highly irregular morphology. The apparent magnitude of the total system is mV=15.4 mag (Weedman 1973) corresponding to MV=-20.4 mag (=75 km s-1 Mpc-1). A foreground star is projected on the host galaxy at a distance of 6 arcsec to the nucleus in north-east direction (see Fig. 1). Therefore, it has been supposed in some early papers that Mkn 110 might be a double nucleus galaxy (Petrosian et al. 1978).
On the other hand the peculiar morphology of Mkn 110 is an indication for a recent interaction and/or merging event in this galaxy (Hutchings & Craven 1988). One can clearly recognize a tidal arm to the west with a projected length of 50 arcsec (corresponding to 35 kpc) and further signs of asymmetry in the disturbed host galaxy on the R-band image (Fig. 1).
Ten years ago we started a long-term variability campaign to study the continuum and emission line intensity variations in selected AGNs. Besides our principal interest in the long-term variability behaviour of these galaxies on its own we want to compare the individual variability properties with those of other galaxies from the international AGN watch campaign (Peterson et al. 1991) (e.g. NGC 5548, Kollatschny & Dietrich 1996) and LAG campaign (Robinson 1994) (e.g. NGC 4593, Kollatschny & Dietrich 1997). Further results on continuum and H variations in Mkn 110 have been published in a recent paper on variability of Seyfert 1 galaxies (Peterson et al. 1998a).
© European Southern Observatory (ESO) 1999
Online publication: April 12, 1999