New six-color intermediate-band photometry and photometric solutions for U Cephei
We describe new six-color intermediate-band photometric observations ofU Cephei, obtained during an interval of consistently low mass-transferactivity. We use the new Wilson eclipsing binary computer program toobtain several photometric solutions, which incorporate the rapidrotation of the hot star. Residual trends for solutions using allobservations show the absorbing effect of the stream between phases 0.7and 0.96. A second set of solutions, omitting data in this phase range,leads to more satisfactory results. Our photometric mass ratio issomewhat smaller than the spectroscopic values found by both Batten(1974) and Tomkin (1981). Differences between our solutions and those ofRafert and Markworth (1991) are probably due to residual contaminationof light curves by circumstellar matter.
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A polarimetric study of U Cephei. I
Polarimetric observations of U Cephei in 1972-78 are presented. Time-and phase-dependent variations in polarization and changes in the shapeof the light curve are discussed. The observations of the 1974-75outburst cannot be explained by an optically thin envelope or disksurrounding the primary component. The observed polarization is an orderof magnitude too small when compared with the amount of additional lightduring the totality of the primary eclipse. It is suggested that theeffective radius of the photosphere of the primary is increased by15-20% during the periods of high mass transfer. The polarizationobservations could then be explained by a simple model containing anoptically thin spherical envelope of outer radius 1.1 times the primaryphotosphere effective radius and an equatorial disk of outer radius 1.7times the primary photosphere effective radius surrounding the primary.The mean electron density is about 1.4 x 10 to the 12th/cu cm in thespherical envelope and 1.6 x 10 to the 12th/cu cm in the preceding and0.9 x 10 to the 12th/cu cm in the trailing sides of the disk, thethickness of which is assumed to be 0.1 times the primary photosphereeffective radius normal to the orbital plane. The variations in theposition angle can be explained if the inclination of the orbit is about83 deg.
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The eclipsing binary U Cephei - New observations and solutions
Observations of the interacting eclipsing binary system U Cephei in thestandard UBV system were obtained at the Rosemary Hill Observatory ofthe University of Florida during the most recent period of activity(October 1974 until May 1976). Double coverage of more than 95 per centof the light curve was obtained. Since analysis of the irregularities inthe light curve depends greatly on an accurate geometrical model, threesolutions by different techniques were attempted. The D. B. Woodsolution failed, since asynchronous rotation of the primary star is notincluded in the model. Reasonable agreement between the Russell-Merrilland Wilson-Devinney solutions was achieved.
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Recent eclipses of U Cephei.
Abstract image available at:http://adsabs.harvard.edu/abs/1979PASP...91..111C
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Request for Photometric Observations of U Cephei
Not Available
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Interstellar Absorption in the North Equatorial Polar Region.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1962ApJ...136..363A&db_key=AST
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A photometric study of U Cephei.
Not Available
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On an apparatus and method for thermoelectric measurements in photographic photometry. II. Application to variable stars.
Not Available
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Variable stars of short period.
Not Available
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