NOAO > Observing Info > Approved Programs > 2003B-0278
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NOAO > Observing Info > Approved Programs > 2003B-0278 |
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PI: Soren Meibom, University of Wisconsin - Madison, meibom@astro.wisc.edu
Address: Dept. of Astronomy, 475 N. Charter Street, Madison, WI 53706, USA
CoI: Robert Mathieu, University of Wisconsin
Title: The effect of binarity on stellar angular momentum evolution in solar- type stars.
Abstract:
Angular momentum is a fundamental property of a star that influences
its internal structure, distribution of chemical composition, and energy
transport. While studies of angular momentum gain and loss in solar-
type stars are extensive, few have confronted the role of binary
companions, despite the fact that most stars are binaries. In fact, the
rotational evolution of a star in a binary can be vastly different from
that of a single star. We propose a thesis study on the impact of
binary companions on stellar angular momentum evolution of solar-type
stars. Specifically, we will observationally study: 1) the rate and
evolution of tidal synchronization and pseudo-synchronization; 2) the
rate and evolution of tidal circularization; and 3) the effect of gaps
cleared by companions on magnetic disk locking. We will accomplish this
by determining comprehensive photometric rotation period distributions
and spectroscopic binary populations in the open clusters NGC2264 (3
Myr), M35 (150 Myr), and M34 (250 Myr). This choice of clusters
provides binaries with ages during the most active period of tidal
angular momentum evolution. Extensive photometric time-series
observations exist with which to define the distribution of stellar
rotation periods for all three clusters. We propose here to acquire
high precision radial velocities and thereby identify binaries and
determine their orbital parameters. These combined datasets will be
unique in their ability to address the rich interplay of orbital and
rotational angular momentum. Thus this work will open a new dimension
in the study of angular momentum evolution in solar-type 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 > 2003B-0278 |
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