High proper motion stars in Kapteyn Selected Area 94

We have applied the astrometric techniques devised by Murray for analysis of 48-inch Schmidt photographic data to SuperCOSMOS scans of UK Schmidt plates centred on Kapteyn's Selected Area 94 (α=2h 53m, δ=0°). In this preliminary study, we combine astrometric data from four short-exposure V-band plates, taken in 1987 August (2 plates) and 1993 August (2 plates), with BVRI photometry from sky-limited plate material, to identify stars with proper motions exceeding 0.1 arcsec yr−1. This paper discusses the completeness of the resulting sample and presents spectroscopy of 30 stars with μ>0.2 arcsec yr−1. Based on the latter observations and the distribution in the [HV, (V−I)] reduced proper-motion diagram, we have classified stars in the complete sample as candidate white dwarfs, main-sequence dwarfs and halo subdwarfs, and derived estimates of the disc and halo luminosity functions.