NOAO >   Observing Info >   Approved Programs >   2006A-0430

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Proposal Information for 2006A-0430


PI: Eric Mamajek, Harvard-Smithsonian Center for Astrophysics, emamajek@cfa.harvard.edu
Address: Radio/Geoastronomy Division, 60 Garden St, MS-42, Cambridge, MA 02138, USA

Title: A New, Nearby, Post-T Tauri Association?

Abstract: The census of nearby young stellar aggregates is likely to be very incomplete, even within 100-200 pc. Statistical comparisons between the census of known embedded clusters and open clusters within 1 kpc suggest that only ~5-10% of embedded clusters survive as bound open clusters to age 100 Myr. The statistics suggest that hundreds of unbound remnants of embedded clusters are likely to exist in within 1 kpc of the Sun. As evidenced by the recent discoveries of the TW Hya association and \eta Cha cluster, some of these remnants may lie within 100 pc of the Sun, and provide useful samples for studying early circumstellar disk evolution and searching for young, luminous exoplanets and brown dwarfs. Through combining data from published astrometric and X-ray source catalogs, I have uncovered what appear to be several previously unknown stellar associations. I am requesting time to measure red optical spectra of candidate low-mass members in the richest, southern candidate group. Measurement of the spectral type, Li 6707A absorption, and H(alpha) emission properties for these stars are critical to establishing their youth, and constraining the age for the new association.


National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360



NOAO >   Observing Info >   Approved Programs >   2006A-0430

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