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4. Summary

For six irregular dwarf galaxies having radial velocities V0 < 300 km/s and situated in the nearby CVn cloud we derived large-scale CCD images in the B, V bands. All the galaxies are clearly resolved into stars. Five of them have been resolved for the first time. Using the luminosity of the brightest blue (and, sometimes, red) stars as a distance indicator, we determined the distances to these galaxies. Except for UGC 7298 with D = 8.6 Mpc, the distances lie in the range of [3.5 - 4.8] Mpc. If the majority of the CVn cloud members take part in the general cosmologic expansion, the objects with the lowest radial velocities are expected to be located on the near side of the cloud. The data derived here do not contradict such a suggestion.

With the distances we have measured all the six galaxies are actually dwarf systems, whose absolute magnitudes lie between -12.3 and -15.6 mag. Judging by their total colours, tex2html_wrap_inline902, all the galaxies are at a stage of active star formation. Two of the six, NGC 4163 and UGC 8308, show a colour increase from the centre toward the periphery, which may indicate the presence of an old stellar population. Accumulation of data on the structure and population of dwarf galaxies in the nearest CVn

cloud, as well as on their location with respect to other members of the complex,will allow to understand the conditions which affect the evolutional status of dwarf stellar systems.


This work was supported by INTAS-RFBR grant No. 95-IN-RU-1390 and RFBR grant No. 97-02-17163.

Copyright by the European Southern Observatory (ESO)