Photometric orbits of seven detached eclipsing binaries

Abstract

Photoelectric light curves of the detached eclipsing binaries V805 Aql, TV Cet, MY Cyg, V478 Cyg, V1143 Cyg, BS Dra, and BK Peg are analyzed. The systems are among those with good spectrographic orbits of both components that are in need of good photometric solutions in order to obtain the absolute properties of the components. The analyses are carried out with a computer program valid for detached systems of spherical or slightly oblate stars in orbits of arbitrary eccentricity. A range of solutions much greater than implied by the internal mean errors of the parameters, is found to give satisfactory fits to the observations. Some of the fits are displayed for a variety of solutions for each system. For the three systems with measurable light variation between eclipses - V478 Cyg, V805 Aql, and MY Cyg - the effect of reflection appears to be substantially less than predicted. Very small, but nonzero, orbital eccentricities are found for four of the systems. The variations of limb darkening with wavelength and with spectral type are found to be in reasonable agreement with predictions from atmospheric theory.