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T.R. Vaccaro, R.E. Wilson (University of Florida)
Simultaneous H\alpha spectroscopy and CCD photometry in BVRI are used to model variable line emission in the eclipsing binary V471 Tau, which consists of a G2 dwarf and a hot white dwarf in a 0.5 day orbit. We modeled the phase dependent H\alpha emission as chromospheric fluorescence on the red star. The model allows for combined absorption and emission lines, with the emission lines arising from localized chromospheric regions of the G2 star. Orbital and rotational effects cause the composite profiles to vary with time. The model is an extension of the general binary star light curve model by Wilson and Devinney (1971, ApJ, 166, 605) and Wilson (1979, ApJ, 234, 1054; 1990, ApJ, 356, 613). The photometry is used to identify any other effects caused by the intrinsic activity of the cool star. The observations were part of a 12 night campaign on several chromospherically active binaries with the SARA 0.9m and Coudé Feed telescopes at Kitt Peak National Observatory. We would like to thank the Southeastern Association for Research in Astronomy for their support and use of the SARA telescope and KPNO for funding the observer at the Coudé Feed.