  We present the results of optical long-slit spectral observations of
interacting system Arp305 carried out at the 6m telescope BTA at the SAO RAS:
the radial variation of gas kinematics and oxygen abundance. This study
continues the series of spectral observations of tidal debris in the
interacting galaxies. Here we pay special attention to the star-forming region
between the interacting galaxies - a tidal dwarf galaxy (TDG) candidate. This
star-forming system appears to be gravitationally bound or close to this
condition. We show that TDG is metal poor in comparison to the parental galaxy.
It can indicate that either the origin of star-forming gas of TDG was very far
from the centre of parent galaxy or its gas has been diluted by the accretion
of metal poor intergalactic gas. Nevertheless the region of the brightest
emission clump in TDG where a current star formation takes place reveals a
noticeable colour excess evidencing a local gas concentration. We pay attention
that TDG is situated in the region of intersection of two gas flows and is in a
process of formation probably caused by the collision of these flows. Low
velocity difference between TDG, NGC 4017 and the gaseous bridge between them
evidences that the lifetime of TDG is restricted by the time of its fall back
onto the parent galaxy.
