Variations in the orbital periods of eclipsing binaries δ Lib and SX Lyn

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Abstract

Variations in the orbital period of eclipsing binaries δ Lib and SX Lyn are studied. It is shown that these variations can be represented with equal accuracy in two ways: either in the form of a superposition of secular decrease and cyclic variations or only in the form of cyclic fluctuations. Cyclic variations in the period of δ Lib in both cases can be due to the presence of a third body in the system. In the case of a quadratic representation, they can be also a consequence of the magnetic activity of the secondary component. For SX Lyn a superposition of two cyclic variations is found for both linear and quadratic representation. The lower-period variations in both cases can be due to the presence of a third body in the system. The longer-period variation can be a consequence of the magnetic activity of the secondary component. The secular decrease in the periods of both systems could be due to a loss of angular momentum due to magnetic braking.

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About the authors

A. I. Khaliullina

Sternberg State Astronomical Institute, Lomonosov Moscow State University

Author for correspondence.
Email: hfh@sai.msu.ru
Russian Federation, Moscow

References

  1. J. F. J. Schmidt, Astron. Nachr. 63, 39 (1865).
  2. J. Stebbins, Publ. Wahsburns Obs., 15, 33 (1928).
  3. R. H. Koch, Astron. J. 67, 130 (1962).
  4. C. Lazaro, M. J. Arevalo, and A. Claret, Monthly Not. Roy. Astron. Soc. 334, 542 (2002).
  5. V. Bakis, E. Budding, A. Erdem, H. Bakis, O. Demircan, and P. Hadrava, Monthly Not. Roy. Astron. Soc. 370, 1935 (2006).
  6. J. Tomkin, Astrophys. J. 221, 608 (1978).
  7. A. Dervisoglu, K. Pavlovski, H. Lehmann, J. Southworth, and D. Bewsher, Monthly Not. Roy. Astron. Soc. 481, 5660 (2018).
  8. T. F. Worek, Publ. Astron. Soc. Pacif. 113, 964 (2001).
  9. E. Geyer, R. Kippenhahn, and W. Strohmeier, Kleine Veröffentlichungen der Remeis – Sternwarte Bamberg № 9, (1955).
  10. B. Wedel and W. Wenzel, Mitt. Veränder. Sterne 1, № 206 (1955).
  11. W. Götz and W. Wenzel, Mitt. Veränder. Sterne 1, № 570, (1961).
  12. D. MacDonald, McCormick Publ. 12, part 5, 51 (1964).
  13. M. A. Svechnikov and Eh. F. Kuznetsova, Vizier On-line Data Catalog: Approximate elements of eclipsing binaries (1990).
  14. B. R. N. O. Project–Eclipsing Binaries database, http://var2.astro.cz/EN/brno/index.php.
  15. Д. Я. Мартынов Переменные звезды (в кн. М. С. Зверев, Б. В. Кукаркин, Д. Я. Мартынов, П. П. Паренаго, Н. Ф. Флоря и В. П. Цесевич, т. 3, Гостехиздат, 464–490, 1947).
  16. А. И. Халиуллина и Х. Ф. Халиуллин, Астрон. журн. 61, 393 (1984).
  17. Z. Eker, F. Soudugan, E. Soydugan, S. Bilir, E. Yaz Gökçe, I. Steer, M. Tüysüz, T. Şenyüz, and O. Demircan, Astron. J. 149, 131 (2015).
  18. Х. Ф. Халиуллин, Астрон. журн. 51, 395 (1974).
  19. N. Ivanova and R. E. Taam, Astrophys. J. 599, 516 (2003).
  20. N. Nanouris, A. Kalimeris, E. Antonopolou, and H. Rjvithis-Livaniou, Astron. and Astrophys. 535, 126 (2011).
  21. J. H. Applegate, Astrophys. J. 385, 621 (1992).
  22. A. F. Lanza, M. Rodono, and R. Rosner, Monthly Not. Roy. Astron. Soc. 296, 893 (1998).
  23. A. F. Lanza and M. Rodono, Astron. and Astrophys. 349, 887 (1999).
  24. А. И. Халиуллина, Астрон. журн. 93, 795 (2016).
  25. А. И. Халиуллина, Астрон. журн. 94, 849 (2017).
  26. А. И. Халиуллина, Астрон. журн. 98, 149 (2021).
  27. А. И. Халиуллина, Астрон. журн. 98, 550 (2021).

Supplementary files

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2. Fig. 1. Differences (O – C) 1 between the observed times of minima δ Lib and those calculated with linear elements (1). Photographic observations are shown as triangles, visual ones as small dots, photoelectric and CCD ones as large dots. Crosses mark the points that were not used in the analysis of period variations.

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3. Fig. 2. Differences (O – C) 11 between the observed moments of minima δ Lib and those calculated with linear elements (2). The solid line shows the theoretical curve for the light-time equation with the parameters from Table 1. The lower part of the figure shows the values ​​of (O – C) 12 obtained by subtracting the theoretical curve for the light-time equation from (O – C) 11. The notations are the same as in Fig. 1.

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4. Fig. 3. Differences (O – C)21 between the observed moments of minima δ Lib and those calculated with linear elements (3). The solid curve is the sum of the theoretical curves for the parabola (3) and the light-time equation with the parameters from Table 2. The lower part of the figure shows the values ​​of (O – C)22 obtained by subtracting both theoretical curves from (O – C)2. The notations are the same as in Fig. 1.

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5. Fig. 4. Differences (O – C)23 obtained by subtracting from the deviations (O – C)1 of the observed moments of minima δ Lib from those calculated with linear elements (3) of the theoretical curve for parabola (3). The solid line shows the theoretical curve for the light-time equation with the parameters from Table 2. The notations are the same as in Fig. 1.

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6. Fig. 5. Differences (O – C)1 between the observed (O) moments of minima of SX Lyn and those calculated (C) with linear elements (5). The notations are the same as in Fig. 1. The crosses mark the points that were not used in the analysis of period changes.

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7. Fig. 6. Differences (O – C)11 between the observed moments of minima SX Lyn and those calculated with the linear elements from the representation (6). The notations are the same as in Fig. 1. The solid line in this figure is the theoretical curve for the light-time equation with the parameters from the first column of Table 4. The lower part of the figure shows the residuals after subtracting the theoretical moments of minima calculated by formula (6) from the observed ones.

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8. Fig. 7. Residuals of (O – C)13 after subtracting the theoretical moments calculated by formula (6) from the observed ones for observations with JD > 2445000. Here, small dots are visual observations, large dots are photoelectric and CCD observations. The solid line in this figure is the theoretical curve for the light-time equation with parameters from the second column of Table 4. The lower part of the figure shows the residuals after subtracting the theoretical minima calculated by formula (6) and the second light-time equation from the observed ones.

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9. Fig. 8. Differences (O – C)21 between the observed times of minima SX Lyn and those calculated with quadratic elements from representation (8). The notations are the same as in Fig. 1. The solid line in this figure is the theoretical curve for the light-time equation with parameters from the first column of Table 5. The lower part of the figure shows the residuals after subtracting the theoretical ones calculated by formula (8) from the observed times of minima.

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10. Fig. 9. Residuals after subtracting the theoretical moments calculated by formula (8) from the observed ones for observations with JD > 2445000. The notations are the same as in Fig. 7. The solid line in this figure is the theoretical curve for the light-time equation with parameters from the second column of Table 5. The lower part of the figure shows the residuals after subtracting the theoretical minima calculated by formula (8) and the second light-time equation from the observed ones.

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