NOAO > Observing Info > Approved Programs > 2013B-0218
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NOAO > Observing Info > Approved Programs > 2013B-0218 |
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PI: Thomas Lebzelter, University of Vienna, thomas.lebzelter@univie.ac.at
Address: Department of Astronomy, Turkenschanzstrasse 17, Vienna A-1180, Austria
CoI: Kenneth Hinkle, NOAO
CoI: Walter Nowotny, University of Vienna
CoI: B. Aringer, University of Vienna
CoI: O. Straniero, INAF-Osservatorio Astronomico di Collurania
Title: Oxygen isotopes, AGB stars, and pre-solar grains
Abstract:
The composition of grains in the pre-solar nebula is determined by
mass ejected by stars. The abundance pattern of these dust particles
can be used to identify the circumstellar envelopes where they formed.
For oxygen in the grains the relative abundances of the isotopes tell us
the mass of the star where the oxygen originated. However, the story is
a complex one since the surface element abundances of low and
intermediate mass stars are modified by a series of mixing events during
the advanced stages of stellar evolution. Many aspects of the mixing of
the products of stellar interior nuclear synthesis are not yet
understood. Currently, the interpretation of the origin of the pre-
solar dust grains is primarily based on stellar evolution models. We
propose to establish an observational basis by determining oxygen
isotopic ratios in a sample of AGB stars of known mass. These ratios
are expected to be very sensitive to the depth reached by the mixing
events, allowing an independent test of stellar evolution and mixing
models.
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 > 2013B-0218 |
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