In this paper we present spectroscopic data on three clusters at moderate distances. The first two, A 3663 and A 3889, with richness class R=2 and distance class D=6 and no previously measured redshifts, were selected from the ACO catalog (Abell et al. 1989), the southern extension of the original Abell catalog (Abell 1958).
Another candidate was selected by visual inspection on a deep plate taken at the prime focus of the ESO 3.6 m telescope. After a check with the DIRA2 and NED databases, we realized that our distant candidate Cl 0053-37 (named after its coordinates at 1950) was at about 8 arcmin south-east of the center of a poor ACO cluster, listed in the ACO Supplementary List of Clusters as S0102. The distance class of S0102 is D=4, and the magnitude of its 10th member is 16.3, but a question mark in the table warns that the measure is not reliable. A note points to a "curious linear concentration S-E of center", i.e. to our candidate, which is indeed characterized by an elongated shape. On the basis of its appearance on the plate, we suspected that this concentration was indeed a background cluster.
The main data concerning the above three clusters are listed in Table 1,
where name, galactic longitude and latitude 
and 
,
Abell type (Regular or IRregular), Bautz-Morgan type,
Abell number 
, richness R, distance class D,
and J magnitude of the 3rd and 10th brightest
member are given for each cluster. We also report the
characteristics of S0102.
We selected the galaxies to be observed in the central parts of the clusters,
typically within 0.5 Abell radii
(
Mpc).
| Cluster name | | | Type | | R | D | m3 | m10 |
| A 3663 | 345.94 | -32.54 | R III | 84 | 2 | 6 | 19.0 | 19.3 |
| A 3889 | 18.16 | -60.00 | R II | 95 | 2 | 6 | 18.6 | 19.4 |
| Cl 0053-37 | 297.94 | -79.54 | IR | -- | -- | -- | -- | |
| S0102 | 298.15 | -79.68 | IR II | 29 | 0 | 4 | 15.0 | 16.3 |