1 Introduction

The discovery and classification of most variables listed in the variable star catalogs were carried out using light curves obtained via photographic patrols. Often, when a star is known to be variable but no periodicity is found and no other information is available it is classified as irregular of type I or L (Kukarkin et al. 1969). In fact, many objects as cataclysmic variables, low-mass X-ray binaries, symbiotic stars, T Tauri and even extragalactic objects like QSO's and BL Lac's can display irregular light variations being, consequently, included among the irregular variables. In the past, a number of such variables have revealed themselves as completely different types of objects as BL Lac (Schmitt 1968), HZ Her - the optical counterpart of Herculis X-1 (Davidsen et al. 1972) and the intermediate polar V1223 Sgr (Steiner et al. 1981).

The existence of a large number of poorly studied irregular variables in the southern hemisphere, and the possibility of discovering objects like cataclysmic variables, X-ray binaries and other types of peculiar objects among them, led us to do a photometric and spectroscopic program in order to classify and better understand such objects. A preliminary report on the results of this study was published by Steiner et al. (1988).