Observing ROSAT sources in an area covering \sim 30 % of the Southern Hemisphere , we found evidences for a great nearby association ( GAYA ) , comprising the proposed associations of Horologium ( HorA ) and the eastern part of Tucana ( TucA ) , formed by at least 44 Post-T Tauri stars .
The stars of the GAYA have similar space velocity components relative to the Sun ( U , V , W ) = ( -9.8 \pm 1.2 , -21.7 \pm 1.1 , -2.0 \pm 2.2 ) km/s and their Li line intensities are between those of the classical T Tauri stars and the ones of the Local Association stars .
The distances of the members of the GAYA cover an interval of \sim 70 pc , compatible with the angular size of \sim 60 \hbox { $ { } ^ { \circ } $ } and in agreement with an initial velocity dispersion of \sim 1.5 km/s and its evolutive age .
We found many other young stars , not members of the GAYA .
We also observed a control region near the equator , covering 700 square degrees , where we found only four young stars .
The overabundance of young stars near the South Pole ( by a factor of five ) seems to show that there may be other young associations not yet characterized .