2001/05/16 by C. A. O. Torres, Torres, C. A. O., G. R. Quast +8
Earth and Planetary Sciences · Physics and Astronomy · #Astrophysics (astro-ph) #FOS: Physical sciences #Geological Studies and Exploration #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0105291
latex file, 5 pages, 3 figures, conference: Young Stars Near Earth: Progress and Prospects, ASP Conference Series ed:Ray Jayawardhana and Thomas Greene
arxiv created 2001/05/16 · openalex publication_date 2001/05/16 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Observing ROSAT sources in an area covering ∼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 ± 1.2, -21.7 ± 1.1, -2.0 ± 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 ∼70 pc, compatible with the angular size of ∼60° and in agreement with an initial velocity dispersion of ∼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.