NOAO >   Observing Info >   Approved Programs >   2013A-0193

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Proposal Information for 2013A-0193


PI: Rachael M. Roettenbacher, University of Michigan, rmroett@umich.edu
Address: Astronomy Department, 500 Church Street, Ann Arbor, MI 48109, United States

CoI: John D. Monnier, University of Michigan

Title: Breaking the Inclination Degeneracy: Accurate Spot Modeling of Young Solar Analogs

Abstract: With the nearly uninterrupted, multi-year, milli-magnitude precision light curves collected by the \emphKepler satellite, the structure and nature of starspots can be studied with unprecedented detail. Using light-curve inversion techniques, we are able to follow starspots as they form and dissipate in order to gain knowledge about spot evolution, differential rotation, and the stellar magnetic dynamo. Our technique for studying differential rotation has already been applied to a \emphKepler target as a pilot study (Roettenbacher et al. 2012). We propose to measure v \sin i for an enlarged sample of spotted, rapidly- rotating stars in the \emphKepler field. Identifying an accurate angle of inclination based on spectroscopically determined v \sin i values and estimates of the period and radius will eliminate the degeneracy of solutions providing accurate surface reconstructions. In addition to determining values for i, we will obtain first spectroscopic estimates of \log g and metallicity needed to determine precise stellar properties. Our program will provide unique constraints on mean field dynamo theory needed to understanding X-ray production, angular momentum and mass-loss evolution of the young Sun. Our proposed targets have already been approved for extended \emphKepler monitoring as part of a funded \emphKepler Guest Observer program.


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NOAO >   Observing Info >   Approved Programs >   2013A-0193

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