Astronomy Reports

, Volume 44, Issue 10, pp 696–700 | Cite as

Statistics of BY Draconis variables

  • I. Yu. Alekseev


A statistical survey of 113 spotted red dwarf stars that are known or suspected BY Draconis variables is presented. Typical indicators of stellar photometric activity—the amplitudes of the rotational modulation and seasonal mean brightness variations ΔV and Δ〈V〉—are compared to the global parameters of the stars. First, photometric variability shows a weak dependence on spectral type; second, ΔV and Δ〈V〉 grow with increasing stellar rotational velocity and decreasing Rossby number, with the dependences saturating at the critical values Vcrit∼15–20 km/s and Rocrit∼0.2–0.3; and third, the Sun as a star fits well into the derived relations. Thus, the spottedness of stars, like other indicators of stellar activity, depends on their global parameters.


Rotational Velocity Weak Dependence Spectral Type Statistical Survey Rotational Modulation 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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  1. 1.
    R. Pallavicini, L. Golub, R. Rosner, et al., Astrophys. J. 248, 279 (1981).CrossRefADSGoogle Scholar
  2. 2.
    M. Mathioudakis, A. Fruscione, J. J. Drake, et al., Astron. Astrophys. 300, 775 (1995).ADSGoogle Scholar
  3. 3.
    D. Montes, M. J. Fernández-Figueroa, E. de Castro, and M. Cornide, Astron. Astrophys. 294, 165 (1995).ADSGoogle Scholar
  4. 4.
    A. Scumanich, Astrophys. J. 171, 565 (1972).ADSGoogle Scholar
  5. 5.
    S. Catalano and E. Marilli, Astron. Astrophys. 121, 190 (1983).ADSGoogle Scholar
  6. 6.
    O. Vilhu and F. M. Walter, Astrophys. J. 321, 958 (1987).CrossRefADSGoogle Scholar
  7. 7.
    I. Yu. Alekseev and R. E. Gershberg, Astron. Zh. 73, 589 (1996) [Astron. Rep. 40, 538 (1996)].Google Scholar
  8. 8.
    B. R. Pettersen, Mem. Soc. Astron. Ital. 62, 217 (1991).ADSGoogle Scholar
  9. 9.
    R. E. Gershberg, M. M. Katsova, M. N. Lovkaya, et al., Astron. Astrophys., Suppl. Ser. 139, 555 (1999).CrossRefADSGoogle Scholar
  10. 10.
    K. G. Strassmeier, D. S. Hall, M. Zeilik, et al., Astron. Astrophys., Suppl. Ser. 72, 291 (1988).ADSGoogle Scholar
  11. 11.
    K. G. Strassmeier, D. S. Hall, F. C. Fekel, and M. Scheck, Astron. Astrophys., Suppl. Ser. 100, 173 (1993).ADSGoogle Scholar
  12. 12.
    G. W. Henry, F. C. Fekel, and D. S. Hall, Astron. J. 110, 2926 (1995).CrossRefADSGoogle Scholar
  13. 13.
    J. T. Hooten and D. S. Hall, Astrophys. J., Suppl. Ser. 74, 225 (1990).CrossRefADSGoogle Scholar
  14. 14.
    G. Cutispoto, R. Pallavicini, L. Pasquini, et al., in Cool Stars, Stellar Systems and the Sun, Ed. by M. S. Giampapa and J. A. Bookbinder, Astron. Soc. Pac. Conf. Ser. 26, 119 (1992).Google Scholar
  15. 15.
    G. Cutispoto, G. Tagliaferri, P. Giommi, et al., Astron. Astrophys., Suppl. Ser. 87, 233 (1991).ADSGoogle Scholar
  16. 16.
    G. Cutispoto, G. Tagliaferri, R. Pallavicini, et al., Astron. Astrophys., Suppl. Ser. 115, 41 (1996).ADSGoogle Scholar
  17. 17.
    D. S. Hall, in The Sun and Cool Stars: Activity. Magnetism. Dynamos, Ed. by I. Tuominen, D. Moss, and G. Rüdiger (Springer, Heidelberg, 1991), p. 353.Google Scholar
  18. 18.
    P. F. Chugainov, Astrofizika 30, 271 (1991).ADSGoogle Scholar
  19. 19.
    N. I. Shakhovskaya, in Flares and Flashes, Ed. by J. Greiner, H. W. Dürbeck, and R. E. Gershberg, Lect. Notes Phys. 454, 61 (1995).Google Scholar
  20. 20.
    M. A. O’Dell, P. Panagi, M. A. Hendry, and A. Collier Cameron, Astron. Astrophys. 294, 715 (1995).ADSGoogle Scholar
  21. 21.
    M. Bünte and S. H. Saar, Astron. Astrophys. 271, 167 (1993).ADSGoogle Scholar
  22. 22.
    G. Tagliaferri, G. Cutispoto, R. Pallavicini, et al., Astron. Astrophys. 285, 272 (1994).ADSGoogle Scholar
  23. 23.
    B. W. Bopp, T. B. Ake, B. D. Goodrich, et al., Astrophys. J. 297, 691 (1985).CrossRefADSGoogle Scholar
  24. 24.
    R. M. Robb and R. D. Cardinal, Inf. Bull. Var. Stars, No. 4270 (1995).Google Scholar
  25. 25.
    R. D. Jeffries, P. B. Byrne, J. G. Doyle, et al., Mon. Not. R. Astron. Soc. 270, 153 (1994).ADSGoogle Scholar
  26. 26.
    B. R. Petterson, D. L. Lambert, J. Tomkin, et al., Astron. Astrophys. 183, 66 (1987).ADSGoogle Scholar
  27. 27.
    G. W. Lockwood, D. T. Thompson, R. R. Radick, et al., Publ. Astron. Soc. Pac. 96, 714 (1984).CrossRefADSGoogle Scholar
  28. 28.
    F. van Leeuwen and P. Alphenaar, ESO Messenger 28, 15 (1982).ADSGoogle Scholar
  29. 29.
    J. R. Stauffer, L. W. Hartmann, J. N. Burnham, and B. F. Jones, Astrophys. J. 289, 247 (1985).CrossRefADSGoogle Scholar
  30. 30.
    B. W. Bopp and F. C. Fekel, Astron. J. 82, 490 (1977).ADSGoogle Scholar
  31. 31.
    B. W. Bopp and F. Espenak, Astron. J. 82, 916 (1977).ADSGoogle Scholar
  32. 32.
    Th. Granzer and K. G. Strassmeier, in Proceedings of the 11th Cambridge Workshop “Cool Stars, Stellar Systems and the Sun,” Ed. by R. J. García López, R. Rebolo, and M. R. Zapatero Osorio, Astron. Soc. Pac. Conf. Ser. (in press).Google Scholar
  33. 33.
    I. Yu. Alekseev and R. E. Gershberg, Astron. Zh. 74, 240 (1997) [Astron. Rep. 41, 207 (1997)].Google Scholar
  34. 34.
    R. W. Noyes, L. W. Hartmann, S. L. Baliunas, et al., Astrophys. J. 279, 763 (1984).CrossRefADSGoogle Scholar

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© MAIK "Nauka/Interperiodica" 2000

Authors and Affiliations

  • I. Yu. Alekseev
    • 1
  1. 1.Crimean Astrophysical ObservatoryCrimeaUkraine

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