Optical Study of the Polar BM CrB in a Low State

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Abstract

We have performed spectroscopic and photometric studies of the poorly explored polar BM CrB. Based on ZTF survey data, we have revealed three brightness states of the polar and evidence of the transition from one-pole to two-pole accretion as the average brightness of the system increases. We show that there are a change in the longitude of the main accretion spot (by @17) and an increase in its extent (by@10) when passing from the low state to the high one. Zeeman Ha absorptions formed in a magnetic field of strength B = 15.5+1  MG are present in the spectra. The cool halo extending from the accretion spot to @1/4  of the white dwarf radius can be the source of these absorptions. Our modeling of the behavior of the Ha emission line shows that the main source of the emission is the segment of the accretion stream near the Lagrange point L1 that is periodically eclipsed by the donor star. The spectra exhibit a cyclotron component forming in the accretion spot. Their modeling by a simple accretion spot model gives constraints on the magnetic field strength, B = 15–40 MG, and the temperature, Te@15 keV.

About the authors

A. I. Kolbin

Special Astrophysical Observatory, Russian Academy of Sciences; Kazan (Volga Region) Federal University

Email: kolbinalexander@mail.ru
357147, Nizhnii Arkhyz, Karachai-Cherkessian Republic, Russia; 420000, Kazan, Russi

N. V. Borisov

Special Astrophysical Observatory, Russian Academy of Sciences

Email: kolbinalexander@mail.ru
357147, Nizhnii Arkhyz, Karachai-Cherkessian Republic, Russia

A. N. Burenkov

Special Astrophysical Observatory, Russian Academy of Sciences

Email: kolbinalexander@mail.ru
357147, Nizhnii Arkhyz, Karachai-Cherkessian Republic, Russia

O. I. Spiridonova

Special Astrophysical Observatory, Russian Academy of Sciences

Email: kolbinalexander@mail.ru
357147, Nizhnii Arkhyz, Karachai-Cherkessian Republic, Russia

I. F. Bikmaev

Kazan (Volga Region) Federal University; Academy of Sciences of Tatarstan

Email: kolbinalexander@mail.ru
Россия, Казань; Россия, Казань

M. V. Suslikov

Special Astrophysical Observatory, Russian Academy of Sciences; Kazan (Volga Region) Federal University

Author for correspondence.
Email: kolbinalexander@mail.ru
357147, Nizhnii Arkhyz, Karachai-Cherkessian Republic, Russia; 420000, Kazan, Russi

References

  1. Афанасьев, Моисеев (V.L. Afanasiev and A.V. Moiseev), Baltic. Astron. 20, 363 (2011).
  2. Бойерманн и др. (K. Beuermann, V. Burwitz, K. Reinsch, A. Schwope, and H.-C. Thomas), Astron. Astrophys. 634, 91 (2020).
  3. Викрамазингхе и др. (D.T. Wickramasinghe, I.R. Tuohy, and N. Visvanathan), Astrophys. J. 318, 326 (1987).
  4. Воелк, Бойерманн (U. Woelk and K. Beuermann), Astron. Astrophys. 306, 232 (1996).
  5. ван Доккум (P.G. van Dokkum), Publ. Astron. Soc. Pacific 113, 1420 (2001).
  6. Зоротович и др. (M. Zorotovic, M.R. Schreiber, and B.T. Gänsicke), Astron. Astrophys. 536, 42 (2011).
  7. Kинг, Канниззо (А.R. King and J.K. Cannizzo), Astrophys. J. 499, 348 (1998).
  8. Книгге и др. (С. Knigge, I. Baraffe, and J. Patterson), Astrophys. J. Suppl. Ser. 194, 28 (2011).
  9. Колбин и др. (А.I. Kolbin, N.A. Serebryakova, M.M. Gabdeev, and N.V. Borisov), Astrophys. Bull. 74, 80 (2019).
  10. Колбин А.И., Борисов Н.В., Письма в Астрон. журн. 46, 868 (2020) [A.I. Kolbin and N.V. Borisov, Astron. Lett. 46, 812 (2020)].
  11. Колбин и др. (A.I. Kolbin, N.V. Borisov, N.A. Serebriakova, V.V. Shimansky, N.A. Katysheva, M.M. Gabdeev, and S.Yu. Shugarov), MNRAS 511, 20 (2022).
  12. Котзе и др. (E.J. Kotze, S.B. Potter, and V.A. McBride), Astron. Astrophys. 579, 77 (2015).
  13. Котзе и др. (E.J. Kotze, S.B. Potter, and V.A. McBride), Astron. Astrophys. 595, 47 (2016).
  14. Кроппер (M. Cropper), Space Sci. Rev. 54, 195 (1990).
  15. Кэмпбелл и др. (R.K. Campbell, T.E. Harrison, A.D. Schwope, and S.B. Howell), Astrophys. J. 672, 531 (2008).
  16. Марш, Швопе (T.R. Marsh and A.D. Schwope), ASSL 439, 195 (2016).
  17. Маски и др. (F. Masci, R. Laher, B. Rusholme, et al.), Publ. Astron. Soc. Pacific 131, 995 (2018).
  18. Cилбер (A.D. Silber), P.hD thesis, MIT, (1992).
  19. Уорнер (B. Warner), Cataclysmic Variable Stars (Cambridge Univ. Press, Cambridge, 1995).
  20. Феррарио и др. (L. Ferrario, J. Bailey, and D. Wickramasinghe), MNRAS 282, 218 (1996).
  21. Феррарио и др. (L. Ferrario, D. de Martino, and B.T. Gänsicke), Space Sci. Rev. 191, 111 (2015).
  22. Фланнери (B.P. Flannery), MNRAS 170, 325 (1975).
  23. Хеллиер (С. Hellier), Cataclysmic Variable Stars (Springer, 2001).
  24. Хорн (K. Horne), Publ. Astron. Soc. Pacific 98, 609 (1986).
  25. Чэнмьюгэм, Далк (G. Chanmugam and G.A. Dulk), Astrophys. J. 244, 569 (1981).
  26. Швопе и др. (A.D. Schwope, K. Beuermann, and S. Jordan), Astron. Astrophys. 301, 447 (1995).
  27. Швопе и др. (A.D. Schwope, K.H. Mantel, and K. Horne), Astron. Astrophys. 319, 894 (1997).
  28. Швопе, Менгель (A.D. Schwope and S. Mengel), Astronomische Nachrichten 318, 25 (1997).
  29. Швопе и др. (A.D. Schwope, M.S. Catalán, et al.), MNRAS 313, 533 (2000).
  30. Швопе и др. (A.D. Schwope, F. Mackebrandt, B.D. Thinius, C. Littlefield, P. Garnavich, A. Oksanen, and T. Granzer), Astronomische Nachrichten 336, 115 (2015).
  31. Шимежек, Вуннер (C. Schimeczek and G. Wunner), Astrophys. J. Suppl. Ser. 212, 26 (2014).
  32. Шкоди и др. (P. Szkody, A. Henden, O.J. Fraser, N.M. Silvestri, G.D. Schmidt, J.J. Bochanski, M.A. Wolfe, M. Agüeros, et al.), Astron. J. 129, 2386 (2005).

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