Abstract
We present here a study of HCG 54 based on deep optical images and spectroscopy, as well as high resolution ion{H}{1} data obtained with the VLA. HCG 54 is embedded in an ion{H}{1} cloud of diameter 12 kpc plus a 20 kpc tidal tail emerging from its western edge. The formation of this tail can be explained by the passage of a dwarf galaxy that we found close to the end of the tail. The central system is surrounded by several optical shells produced by the interaction of two disks. HCG 54a is probably the main object of the system, while HCG 54cd might constitute the remnent of the second merging body.
