Young, Peter

Contact Email: pyoung@cfa.harvard.edu
Institute: Harvard-Smithsonian Center for Astrophysics
First Coauthor: Andrea Dupree
Institute: Harvard-Smithsonian Center for Astrophysics
Subject Area: Binary Stars: Non-interacting
Waveband: Far Ultraviolet
Technique: Spectroscopy
Presentation: Poster Display
Title: FUSE observations of active binaries
Abstract: RS CVn systems and contact binaries composed of cool stars are chromospherically active presumably resulting from magnetic activity caused by rapid rotation and deep convective layers. We report results from a FUSE campaign to monitor 4 systems: 44$\iota$ Boo (HD 133640), II Peg (HD 224085), $\lambda$ And (HD 222107), and $\sigma$ Gem (HD 62044) over their orbital periods that range from 6.4 hours to 20.5 days. The strong C III ($\lambda$977) and O VI ($\lambda$1032) emission lines can show variability with phase as well as flaring episodes. FUSE fluxes can be used to derive an emission measure distribution over the transition region for comparison with chromospheric and coronal models obtained from IUE and EUVE spectra. A comparison of the spectra is made with single stars from the FUSE Cool Star Survey. FUSE spectra of the contact binary, 44$\iota$ Boo, resolve the individual components of the system and allow the surface distribution of transition region flux to be estimated.