NOAO > Observing Info > Approved Programs > 2009B-0057
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NOAO > Observing Info > Approved Programs > 2009B-0057 |
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PI: Kim Venn, University of Victoria, kvenn@uvic.ca
Address: Department of Physics and Astronomy, PO Box 3055, Victoria, BC, V8W 3P6, Canada
CoI: David Lambert, University of Texas at Austin
CoI: Thomas Puzia, Herzberg Institute for Astrophysics
Title: Search for Circumstellar Material around the Ultra Metal-Poor Stars
Abstract:
The three "ultra metal-poor" stars HE1327-2326, HE0107-5240, and HE0557-4840,
are thought to represent yields of the most metal-poor supernova and,
therefore, observationally constrain the earliest stages of chemical
evolution in the Universe. However, detailed comparison of their chemical
compositions show remarkable similarities to chemically peculiar stars, which
are stars with initially solar metallicities that now appear metal-poor due
to a separation in their dust and gas components. If these stars are
metal-poor due to chemical peculiarities only, then they are not fossils of
the earliest epochs of chemical evolution in the Universe. A simple and
definitive test of this hypothesis is to search for circumstellar material
around them - even the null result is interesting since the absense of a
dusty disk would confirm that these stars are truly metal-poor. While near-IR
(JHK) colors show no near-IR excesses, the debris disks of most chemically
peculiar stars do not outshine the star until beyond 10 microns (thus in the
N and Q-bands). Thus, we propose Gemini-S TReCS N and Q-band imaging to test
for the presence of circumstellar material around these stars.
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 > 2009B-0057 |
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