NOAO > Observing Info > Approved Programs > 2009A-0178
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NOAO > Observing Info > Approved Programs > 2009A-0178 |
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PI: Sergio Dieterich, Georgia State University, dieterich@chara.gsu.edu
Address: Department of Physics and Astronomy, Atlanta, GA, 30302, USA
CoI: Todd Henry, Gerogia State University
CoI: David Golimowski, Space Telescope Science Institute
Title: GJ 433: Resolving a Suspected Binary Near the Stellar/Substellar Boundary
Abstract:
We propose to obtain high resolution images of the suspected very low mass
binary GJ 433 AB using NIRI+ALTAIR on Gemini North. The duplicity of GJ 433
was first indicated by a perturbation in Hipparcos data, and later by speckle
observations (Bernstein, 1997). Our own HST/NICMOS observations revealed the
companion but the 75 mas pixels do not allow us to measure an accurate
separation or position angle. The combination of Hipparcos astrometry, the
single IR speckle measurement, and tentative NICMOS photometry indicate that
the B component has a mass very near the hydrogen burning mass limit, between
0.122 and 0.088 solar masses. Although much work has been done in the field
of brown dwarfs during the past decade, the fundamental question of where the
exact boundary between stellar and substellar object lies is still largely
not addressed due to the lack of reliable observational tests that
discriminate between the most massive brown dwarfs and the least massive
stars. Characterizing objects near this boundary is a fundamental aspect of
the PI's doctoral thesis. Here we propose to observe GJ 433 twice to obtain
J, H, and K photometry and begin mapping the orbit, which has a period of
about 1.5 years from the Hipparcos data, to provide a crucial point in the
Mass-Luminosity Relation near the end of the stellar main sequence.
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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NOAO > Observing Info > Approved Programs > 2009A-0178 |
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