Photometric study of MY Cyg.

Orbital Solutions and Absolute Elements of the Eclipsing Binary My Cygni

“…Later work by Popper (1971) included a spectroscopic analysis, indicating components of almost equal mass, and a discussion of the Am metallic-line characteristics. Williamon (1975) noted that the very similar primary and secondary eclipses had been reversed in the work by Popper (1971). With this correction, Popper & Etzel (1981) presented a solution of their photometric data.…”

“…A modern light curve was obtained by Coughlin (2007) expressly for measuring the current displacement of the secondary eclipse. He obtained differential BVRI photometric measurements on three nights, and used the same comparison star as Williamon (1975). His primary eclipse coverage began after first contact and ended slightly past mid-eclipse.…”

“…In the first detailed analysis of the system, Williamon (1975) recognized that the secondary had been displaced from phase 0.50 over the 45 years prior to his study and speculated that it was due to apsidal motion. Williamon found secondary minimum at phase 0.5022, and he derived e = 0.010 and ω = 69.…”

“…This paper is a re-examination of the photometric data and the orbital solution by Williamon (1975). His results were obtained with the Russell-Merrill method on 16-point normals outside of eclipse and 4-point normals inside eclipse.…”

On the apsidal motion of MY Cygni

“…Min. = HJD 2 441 587.64061 + 4.005188234 · E. Besides those minima given in Table 1, we added the photoelectric times of minimum obtained by Pohl & Kizilirmak (1964, 1966, 1975, Williamon (1975, his Table 8). A total of 57 reliable photoelectric times of minimum light were used in our dataset, 26 secondary eclipses being among them.…”