High proper motion stars in Kapteyn Selected Area 94

We have applied the astrometric techniques devised by Murray for analysis o f 48-inch Schmidt photographic data to SuperCOSMOS scans of UK Schmidt plat es centred on Kapteyn's Selected Area 94 (alpha =2(h) 53(m), delta =0 degre es). 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 discusse s the completeness of the resulting sample and presents spectroscopy of 30 stars with mu >0.2 arcsec yr(-1). Based on the latter observations and the distribution in the [H-V, (V-I)] reduced proper-motion diagram, we have cla ssified stars in the complete sample as candidate white dwarfs, main-sequen ce dwarfs and halo subdwarfs, and derived estimates of the disc and halo lu minosity functions.