NOAO >   Observing Info >   Approved Programs >   2012B-0424

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Proposal Information for 2012B-0424


PI: John Gizis, University of Delaware, gizis@udel.edu
Address: Department of Physics and Astronomy, 217 Sharp Lab, Newark, DE 19716, USA

CoI: Philip Castro, University of Delaware

Title: Completing the nearby L dwarf sample

Abstract: We are using the WISE and 2MASS infrared sky survey to identify nearby bright L-type brown dwarfs close to the Galactic Plane, where 2MASS or SDSS-based surveys could not reliably identify them. In this proposal, we request optical spectroscopy of ten new bright L dwarfs, which will serve as new standards for detailed studies of substellar objects. We argue that optical spectroscopy provides important information that cannot be determined from near-infrared spectroscopy we have already obtained: The optical features are better temperature indicators, lithium is a mass/age indicator, H alpha is a chromospheric activity indicator, and the molecular bandheads are sensitive to surface gravity. Our targets include the reddest field L dwarf known, which uniquely proves extremely cloudy substellar atmospheric conditions, and the two closest L7-L8 dwarfs in the northern hemisphere.


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 >   2012B-0424

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