PI: Styliani Kafka, Indiana Unviersity, email@example.com
Address: Astronomy Department, Swain Hall West, Bloomington, IN 47405, US
CoI: Kent Honeycutt, Indiana University
Title: Chromospheric Activity in M Dwarfs and Changes in the CV Mass Transfer Rate
Abstract: Most types of compact binary systems have variable mass transfer rates (\dotM) on many time scales. These effects are often attributed to magnetic activity on the mass-losing secondary star. However, these theories have little or no direct observational evidence because the usual indicators for stellar activity are masked by emission from the accretion disk. We propose to acquire near-infrared spectra to test the hypothesis that \dotM is controlled by activity on the secondary star, using activity-sensitive ratios of the strengths of absorption features arising from the secondary star in cataclysmic variables (CVs). The outburst recurrence intervals of dwarf nova (DN) are determined by \dotM, permitting a test by comparing the activity level in DN having very different outburst intervals but similar orbital periods. We will also obtain spectra in the low state of VY Scl stars, whose low states have been attributed to stellar activity on the secondary star.
National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360