NOAO >   Observing Info >   Approved Programs >   2001B-0150

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Proposal Information for 2001B-0150


PI: Iain Neill Reid, Space Telescope Science Institute, inr@stsci.edu
Address: 3700 San Martin Drive, Baltimore, MD 21218, USA

CoI: Kelle L. Cruz, University of Pennsylvania
CoI: John E. Gizis, IPAC, Caltech
CoI: J. Liebert, University of Arizona

Title: Finding the Neighbours

Abstract: We are engaged in a long-term project which combines 2MASS and POSS II data with other catalogues to complete the census of M and L dwarfs within 20 parsecs of the Sun. Our current program utilises two techniques to identify nearby dwarfs with spectral type \geM5: direct search of the 2MASS database for point sources with (J-K)>1.1 and appropriate JHK magnitudes; and cross-referencing Luyten's NLTT catalogue against 2MASS, using (m_r-K) as a luminosity calibrator. Building on our initial observations, we have identified an all-sky sample of 500 (J-K)-selected late-M/early-L candidates, together with 600 NLTT dwarfs with 14 < m_r < 19.5. We propose to use intermediate resolution spectroscopy to determine accurate distances and luminosities, and characterise the level of chromospheric activity. Approximately two-thirds of the sample is accessible with either Goldcam on the 2.1-metre or the R-C Spectrograph on the CTIO 1.5-metre; for the remainder, we propose to use the R-C spectrographs on the KPNO and CTIO 4-metre telescopes. Our goal is a definitive determination of the stellar luminosity function at faint magnitudes, and hence the stellar mass function in the vicinity of the hydrogen-burning limit.


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



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