NOAO >   Observing Info >   Approved Programs >   2005A-0120

Small NOAO Logo

Proposal Information for 2005A-0120


PI: James D. Neill, University of Victoria, neill@uvic.ca
Address: Physics Department, 3800 Finnerty Road, Victoria, BC V8P 1A1, Canada

CoI: Michael M. Shara, American Museum of Natural History

Title: The Rest of the Iceberg: Finding Faint Cataclysmic Variables

Abstract: Theories of cataclysmic variable (CV) star evolution predict that the current catalog of these objects represents only the tip of the iceberg. CVs arise in binary star systems whose components interact. As angular momentum is lost in these systems (through mass transfer) the separation of the components, and thus their orbital period, decreases. This process slows as the secondary begins to dominate the angular momentum reservoir and reaches a minimum at a period of ~ 1.5 hours. \it The resulting pile-up of systems which must spend ~ 90% of their lifetime very near this limit has yet to be confirmed observationally. We have begun one of the first systematic surveys capable of setting meaningful constraints on this putative population of short period CVs. Using the newly available 8K mosaic camera on the MDM 2.4m Hiltner telescope over six nights (29 May - 03 June 2001) we monitored a sufficient number of stars (10^5.5) with the photometric accuracy and time sampling required to carry out a definitive test of the theory. We propose to spectroscopically confirm a list of 12 candidate CVs using the RC Spectrograph with the T2KB CCD on the KPNO 4m telescope. The resulting catalog of bone fide CVs will test if the currently observed paucity of these objects with periods near 1.5 to 2 hours is purely due to observational sampling limitations or if the theory itself needs substantial revision.


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 >   2005A-0120

noaoprop-help@noao.edu

Small NOAO Logo