The CFHT Open Star Cluster Survey. I. Cluster Selection and Data Reduction

We present this paper in conjuction with the following as the first resultsin the CFHT Open Star Cluster Survey. This survey is a large BVR imaging dataset of 19 open star clusters in our Galaxy. This data set was taken with theCFH12K mosaic CCD (42' X 28') and the majority of the clusters were imagedunder excellent photometric, sub-arcsecond seeing conditions. The combinationof multiple exposures extending to deep (V ~ 25) magnitudes with short (< 10second) frames allows for many different studies. The primary aim of thissurvey is to catalogue the white dwarf stars in these clusters and establishobservational constraints on the initial-final mass relationship for thesestars and the upper mass limit to white dwarf production. Additionally, we hopeto better determine the properties of the clusters, such as age and distance,and also test evolution and dynamical theories by analyzing luminosity and massfunctions. In order to more easily incorporate this data in further studies, wehave produced a catalogue of positions, magnitudes, colors, and stellarityconfidence for all stars in each cluster of the survey. This paper is intendedboth as a source for the astronomical community to obtain information on theclusters in the survey and as a detailed reference of reduction procedures forfurther publications of individual clusters. We discuss the methods employed toreduce the data and compute the photometric catalogue. The scientific resultsfor each individual cluster and global results from the study of the entiresurvey will be presented in further publications (results for the rich old opencluster NGC 6819 immediately follow this paper).Comment: 4 Figures and 3 Tables available in higher resolution at ADS. Accepted for Publication in AJ -- Kalirai et al. 2001a, 122, 257. Update