NOAO >   Observing Info >   Approved Programs >   2004B-0253

Small NOAO Logo

Proposal Information for 2004B-0253


PI: Heather Osborne, New Mexico State University, hosborne@cosmos.nmsu.edu
Address: Department of Astronomy, Box 30001/MSC 4500, Las Cruces, NM 88003, USA

CoI: Tom Harrison, New Mexico State University

Title: CV Secondary Star Masses: The Return to Photometry

Abstract: It has become clear that our understanding of the nature and evolutionary history of cataclysmic variable (CV) stars is incomplete. Pinsonneault et. al. (2002) have suggested a bimodal distribution for CV secondary stars which could cause chemical abundance anomalies (other possible causes mentioned below). Testing these theories requires knowledge of CV system parameters and chemical abundances. Using infrared spectroscopy (OSIRIS and the IRTF's SPEX), Harrison et al.(2002) have identified several CVs with peculiar abundances (levels of ^\rm 13C enhancement yielding ^\rm 12C/^\rm 13C ratios of 3; normal is 89!). More information is needed to determine the reason for these anomalies. To help solve these problems, we must better understand CV system properties. One crucial parameter we require for \it both components in these systems is mass. System orbital inclinations, used with optical, phase-resolved radial velocity data, will yield this information. We request two runs of four nights apiece with SQIID to measure the infrared ellipsoidal variations of thirteen secondary stars with periods between three and ten hours, allowing us to derive their orbital inclinations.


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 >   2004B-0253

noaoprop-help@noao.edu

Small NOAO Logo