NOAO > Observing Info > Approved Programs > 2009B-0328
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NOAO > Observing Info > Approved Programs > 2009B-0328 |
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PI: Robert Mathieu, University of Wisconsin - Madison, mathieu@astro.wisc.edu
Address: Department of Astronomy, 475 North Charter Street, Madison, WI 53706, USA
CoI: Aaron Geller, University of Wisconsin - Madison
CoI: Natalie Gosnell, University of Wisconsin - Madison
CoI: Andrew Szentgyorgyi, Harvard-Smithsonian Center for Astrophysics
Title: The Formation and Evolution of Blue Stragglers in Open Clusters
Abstract:
The dynamical dances that take place during binary encounters in
open star clusters lead to stellar exchanges, binary orbit evolution,
close stellar passages, mass transfer, mergers, and stellar collisions,
resulting in a rich array of ”anomalous” stars such as blue
stragglers and sub-subgiants. In order to better understand these new
evolutionary paths, we propose observations seeking to detect magnetic
fields, secondary stars, and rapid rotation in blue stragglers and other
stars of the old open clusters NGC 188, NGC 6819 and NGC 7789.
Specifically we propose to use the MMT/Hectochelle at Ca H and K to
search for magnetic activity as a proxy for the presence of magnetic
fields. These results will reflect directly on the angular momentum
evolution of blue stragglers. We also propose to obtain high S/N
spectra at the Ca triplet in order to search for main-sequence secondary
stars within blue straggler binaries, a critical test of the formation
of blue stragglers from triple systems. Finally, we will search for
rapidly rotating stars on the main sequences that may be blue straggler
analogues resulting from stellar collisions.
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-0328 |
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