1996A&A...311..446G

We report the observation of a group of 16 red (V-I>2) galaxies, in the magnitude range 22≤V≤25.5, within a projected distance of 30" (∼0.2h^–1Mpc for h=H₀/75km/s/Mpc) of the ultra-steep spectrum radio source 1443-198 at z=0.753. The colours of the galaxies range from the cut-off at V-I=2.0 to V-I=3.3. Eight galaxies are redder than V-I=2.3 and three are redder than V-I=3.0. Some objects with I≃23 are undetected at the magnitude limit of V=25.5. This confirms previous results on the presence of a very red envelope in some distant clusters and suggests that a fraction of cluster ellipticals are already old at z≃0.75. The radio galaxy has colours and a 4000A break amplitude typical of evolving E/S0 galaxies, and shows signs of interaction with other objects in its immediate vicinity.