We describe a large sample of 598 galaxy clusters and rich groups discovered in the data of the Faint Sky Variability Survey .
The clusters have been identified using a fully automated , semi-parametric technique based on a maximum likelihood approach applied to Voronoi tessellation , and enhanced by colour discrimination .
The sample covers a wide range of richness , has a density of \sim 28 clusters deg ^ { -2 } , and spans a range of estimated redshifts of 0.05 < z < 0.9 with mean \langle z \rangle = 0.345 .
Assuming the presence of a cluster red sequence , the uncertainty of the estimated cluster redshifts is assessed to be \sigma \sim 0.03 .
Containing over 100 clusters with z > 0.6 , the catalogue contributes substantially to the current total of optically-selected , intermediate-redshift clusters , and complements the existing , usually X-ray selected , samples .
The FSVS fields are accessible for observation throughout the whole year , making them particularly suited for large follow-up programmes .
The construction of this FSVS Cluster Catalogue completes a fundamental component of our continuing programmes to investigate the environments of quasars and the chemical evolution of galaxies .
We publish here the list of all clusters with their basic parameters , and discuss some illustrative examples in more detail .
The full FSVS Cluster Catalogue , together with images and lists of member galaxies etc. , will be issued as part of the “ NOAO data products ” , and accessible at http : //www.noao.edu/dpp/ .
We describe the format of these data and access to them .