Abstract
ABSTRACT. T-Tauri stars are normally found in associations and/or in gas and dust clouds. Recently, however, a few objects have been found in the southern hemisphere showing characteristics of post-T Tauri stars, but that are far from any cloud or association. Typical objects of this kind are V4046 Sgr, CoD-27ll363, AS 218, FK Ser, AB Dor, TW Hya. Spectra around B were obtained for these objects and some of them were also observed photometrically. They show periodic or quasi-periodic light variations, indicati ve of rotational modulation, superposed on an erratic variation due probably to intense chroinospberlc activity The amplitudes of the variation in different colors, if interpreted as rotational modulation, may be incompatible with a cold spot model . Ultraviolet and infrared excesses are observed in most of these objects. Keq #I : STARS-PRE- AIN SEQUENCE -- STAPS-T TAURI
