A photometric study of the eclipsing binary V 1073 Cygni

Multi-color light curves and orbital period research of eclipsing binary V1073 Cyg

“…The period decrease had been well discussed (Aslan & Herczeg, 1984;Wolf & Diethelm, 1992;Sezer, 1993;Morris & Naftilan, 2000;Yang & Liu, 2000). We tried to fit the O-C curve with downward parabola…”

“…Radial veloc-q = 0.303(17) was presented by Pribulla et al (2006) based on their radial-velocity curve. And the fill-out factor has been reported many times, such as f = 0.007 and f = 0.008 (Kondo, 1966;Leung & Schneider, 1978;Ahn et al, 1992;Sezer, 1993Sezer, , 1994, f = 0.19 (Jafari et al, 2006), and f = 0.20 (Sezer, 1996).…”

“…Aslan & Herczeg (1984) found that the period decreased about 0.4 seconds in 1976 using 25 photoelectric and some photograph epochs of minima since 1962, then Wolf & Diethelm (1992) made a new O-C analysis with adding 16 photoelectric times of light minima and detected a constant decrease. One year later, Sezer (1993) made a analysis using 29 photoelectric data and reported that the period was decreasing by 3.12(±0.17) seconds per century (i.e. P = −7.8 × 10 −10 days · cycle −1 ).…”

V1073 Cygni: A New Light Curve and Analysis

“…( 1). (2) Wolf & Deithelm (1992) and Sezer (1993) each derived a quadratic ephemeris to Ðt the photoelectric data, but the linear ephemerides in equations ( 1) and (2) seem to describe fully the times of minima of V1073 Cygni. The FIG.…”

“…Ahn et al (1992) analyzed all three sets of light curves with the program LIGHT2, assuming convective behavior, q \ 0.32, and K (consistent with T 1 \ 6700 an F2 spectral type), and found 8% overcontact with both components near the terminal-age main sequence (TAMS). Sezer (1993Sezer ( , 1994 obtained photoelectric B and V light curves, listed his data points, and used the Wilson-Devinney computer program to Ðnd 3% overcontact and q \ 0.436, assuming radiative behavior and K. These light T 1 \ 8570 curves were reanalyzed in Sezer (1996) assuming convective behavior and K, Ðnding 19%È22% overcontact, T 1 \ 6700 and q \ 0.306 ^0.002, in much better agreement i \ 69¡ .4, with the spectroscopic values. Sezer did not publish his normal points, so the present authors calculated a set of normal points and placed them in the IAU Archives of Unpublished Observations of Variable Stars, File 342E.…”