The Great Austral Nearby Young Association 1
Abstract. 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 th...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.315.3948 2023-05-15T18:22:35+02:00 The Great Austral Nearby Young Association 1 Ray Jayawardhana Thomas Greene C. A. O. Torres G. R. Quast C. H. F. Melo The Pennsylvania State University CiteSeerX Archives 2001 application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.315.3948 http://arxiv.org/pdf/astro-ph/0105291v1.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.315.3948 http://arxiv.org/pdf/astro-ph/0105291v1.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://arxiv.org/pdf/astro-ph/0105291v1.pdf text 2001 ftciteseerx 2016-09-04T00:05:44Z Abstract. 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. 1. Text South pole Unknown Austral Hora ENVELOPE(15.744,15.744,67.445,67.445) South Pole |
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ftciteseerx |
language |
English |
description |
Abstract. 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. 1. |
author2 |
The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
Ray Jayawardhana Thomas Greene C. A. O. Torres G. R. Quast C. H. F. Melo |
spellingShingle |
Ray Jayawardhana Thomas Greene C. A. O. Torres G. R. Quast C. H. F. Melo The Great Austral Nearby Young Association 1 |
author_facet |
Ray Jayawardhana Thomas Greene C. A. O. Torres G. R. Quast C. H. F. Melo |
author_sort |
Ray Jayawardhana |
title |
The Great Austral Nearby Young Association 1 |
title_short |
The Great Austral Nearby Young Association 1 |
title_full |
The Great Austral Nearby Young Association 1 |
title_fullStr |
The Great Austral Nearby Young Association 1 |
title_full_unstemmed |
The Great Austral Nearby Young Association 1 |
title_sort |
great austral nearby young association 1 |
publishDate |
2001 |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.315.3948 http://arxiv.org/pdf/astro-ph/0105291v1.pdf |
long_lat |
ENVELOPE(15.744,15.744,67.445,67.445) |
geographic |
Austral Hora South Pole |
geographic_facet |
Austral Hora South Pole |
genre |
South pole |
genre_facet |
South pole |
op_source |
http://arxiv.org/pdf/astro-ph/0105291v1.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.315.3948 http://arxiv.org/pdf/astro-ph/0105291v1.pdf |
op_rights |
Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
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1766201989359730688 |