  The S-tree method is used to estimate the redshift of the core of Coma
cluster - $cz = 6953$ km s$^{-1}$ and dispersion $\sigma=949$ km s$^{-1}$. The
existence of three subgroups of galaxies is revealed, one of them is associated
with the cD galaxy NGC 4874, another - with NGC 4889. It is argued that these
subgroups are 'galaxy associations', i.e. galactic dynamical entities moving
through the main cluster. The non-stationarity of the dynamical processes
ongoing in the Coma core is concluded.
