The Edinburgh-Cape Blue Object Survey - IV. Zone 3: Galactic latitudes -40? > b > -50?

Results for Zone 3 of the Edinburgh-Cape (EC) Blue Object survey are presented. This zone covers that part of the South Galactic Cap between 40? and 50? from the Galactic plane and south of about -12. ? 3 of declination. EC Zone 3 contains 53 UK Schmidt Telescope fields covering about 1400 deg2 in which we find some 534 blue objects, including hot subdwarfs (~39 per cent), white dwarfs (~21 per cent), cataclysmic variables (~2 per cent) and some starlike galaxies (~9 per cent). A further 178 cooler stars observed in the survey, including lowmetallicity F- and G-type stars, are also listed. Both low-dispersion spectroscopic classification and UBV photometry are presented for almost all of the hot objects and either spectroscopy or photometry (sometimes both) for the cooler ones. [ABSTRACT FROM AUTHOR]