NOAO >   Observing Info >   Approved Programs >   2012B-0274

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Proposal Information for 2012B-0274


PI: Laura Ingleby, University of Michigan, lingleby@umich.edu
Address: Department of Astronomy, 830 Dennison Building, 500 Church St, Ann Arbor, MI 48109, USA

CoI: Nuria Calvet, University of Michigan
CoI: Kevin Luhman, Penn State University
CoI: Suzan Edwards, Smith College
CoI: Melissa McClure, University of Michigan

Title: Peering through the Magnetospheres of Slowly Accreting T Tauri Stars

Abstract: Numerous observations support the theory that during pre-main sequence evolution, young stars accrete material from their disks via magnetospheric accretion. However, characterizing the final stages of accretion has proven difficult. Chromospheric emission masks evidence of weak accretion flows in low resolution spectra and very few observations exist with the resolution to detect predicted narrow accretion features on the spectral lines. We propose to use the high resolution near-infrared instrument, Phoenix, on the 4m telescope at Kitt Peak National Observatory to monitor the He I (lambda)1.083 (micron) and Br(gamma) (lambda)2.16 (micron) lines towards 3 low accretors in the Taurus star forming region. We will observe the lines over the rotational period of the star to determine how accretion streams change as the source rotates. He I and Br(gamma) arise from material at different temperatures, originating from separate regions in the accretion flows, so we will produce a comprehensive map of the magnetosphere at low accretion rate. By characterizing accretion near its end, we will provide constraints on the physics of circumstellar disk dissipation.


National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360



NOAO >   Observing Info >   Approved Programs >   2012B-0274

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