NOAO >   Observing Info >   Approved Programs >   2006A-0005

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Proposal Information for 2006A-0005


PI: Thomas E Harrison, New Mexico State University, tharriso@nmsu.edu
Address: Astronomy Department, Box 30001/MSC4500, Las Cruces, NM 88003, USA

CoI: Randy Campbell, W. M. Keck Observatory
CoI: Jim Lyke, W. M. Keck Observatory
CoI: Steve Howell, NOAO/WIYN
CoI: Paula Szkody, University of Washington
CoI: France Cordova, University of California, Riverside
CoI: Doug Hoffman, New Mexico State University
CoI: Joseph Wellhouse, New Mexico State University
CoI: Jillian Bornak, New Mexico State University

Title: Can Classical Novae Eruptions Occur on Highly Magnetic White Dwarfs?

Abstract: We have recently completed a K-band spectroscopic survey of magnetic, and non-magnetic cataclysmic variables (CVs). We find that the secondary stars in 19 of 20 non-magnetic CV systems are deficient in carbon. In addition, several of these objects show enhanced levels of ^\rm 13CO. These observations, combined with UV detections of enhanced levels of nitrogen suggest CNO-cycle material has been produced or accreted by the secondary stars. In stark contrast, our IR spectroscopy of magnetic ``AM Her'' systems (``Polars'') shows that their secondary stars are completely normal! \it This discovery suggests that the evolutionary histories of magnetic and non-magnetic CVs are different. However, if strong magnetic fields can suppress classical novae eruptions, this might allow the evolutionary histories to be reconciled. We propose to obtain low resolution IR spectroscopy using NIRC on Keck I of several classical novae that have been proposed to be Polars to search for cyclotron emission. If such features are detected, we will be able to estimate the magnetic field strength and confirm the highly magnetic nature of their white dwarf primaries. This confirmation could dramatically affect our theories about close-binary evolution.


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