A quarter of the 215 known galaxies with radial velocities V0 < 500 km/s are located in a relatively small area: R.A.=, D.= in the Canes Venatici constellation. This prominent concentration of the nearby galaxies (see Fig. 1 (click here)) consists of several partially separated groups whose members were defined differently by several authors (Karachentsev 1966; de Vaucouleurs 1975; Kraan-Korteweg & Tammann 1979; Vennik 1984; Tully 1988). The complex of galaxies in the Canes Venatici is populated mostly by objects of late morphological types. It does not have a common dynamical center usually associated with one luminosity-dominated galaxy.
Unlike other nearby groups of galaxies concentrated around M 81, M 101 and NGC 5128, the diffuse cloud in the Canes Venatici has not many galaxy distances known. Until 1995, the distance moduli determined from Cepheids and the brightest stars were obtained only for four galaxies: IC 4182 (Sandage & Tammann 1982), DDO 154 (Carignan & Beaulieu 1989), DDO 168 (Bresolin et al. 1993) and UGC 8508 (Karachentsev et al. 1994). Recent distance estimates based on the brightest stars have been derived for 11 irregular dwarf members of the cloud by Georgiev et al. (1997) and Makarova et al. (1997). Below, we present new photometric distances for 18 galaxies in the area under consideration. The rest of the galaxies in the Canes Venatici complex have been observed at the 6 m telescope of Special Astrophysical Observatory of the Russian Academy of Sciences and the 2.56 m Nordic Optical Telescope. The reduction of the data obtained is now near completion.
Figure 1: The distribution of galaxies with corrected radial velocities < 500 km/s in the Canes Venatici constellation in equatorial coordinates. Each galaxy is marked by its NGC or UGC number and its radial velocity (in km/s)