A study of optically featureless objects from the EC Survey: searching fornew southern BL Lac objects

In an attempt to discover new southern BL Lac objects, 14 optically feature less objects from the Edinburgh-Cape Survey were selected. Optical polarime try and spectroscopy, radio and IR observations were carried out in order t o improve their classifications. The 14 objects were examined according to special criteria that are described. Their UBV and JHK colour-colour distri butions, spectrograms, radio observations and visible-region polarimetry we re utilized to conclude that the selected objects are not BL Lacs. Most of them are apparently not extragalactic objects. It is suggested that four of the 14 candidates are DC white dwarfs, one is a QSO, three are DA white dw arfs or sdB subdwarfs, one is a cataclysmic variable, one is a DAO/sdO and another is possibly a DA+dM binary (composite system with a 'primary' hot w hite dwarf and a 'secondary' M-type main-sequence dwarf) or a cataclysmic v ariable. One object is likely to be a subdwarf, while two remain unclassifi able.