Rotational Modulation in Be Stars

  • L. A. Balona
Part of the Astrophysics and Space Science Proceedings book series (ASSSP, volume 31)


The broad peaks in the periodograms of the light variations of Be stars do not resolve into individual frequencies even in a long time series. Recent CoRoT observations, in particular, clearly demonstrate their stochastic nature. These peaks, which have frequencies indistinguishable from the rotational frequency and its first harmonic, have generally been attributed to l = 2 nonradial pulsation (NRP). Stochastic variation with the rotational period is an inevitable consequence of localized mass loss for any mass-loss mechanism, including NRP. It is evident that the broad peaks are just a result of co-rotating circumstellar gas clouds. A simple model in which the mass loss is a result of magnetic flaring explains all major characteristics of Be stars.


Rotational Velocity Spectral Type Light Variation Circumstellar Disk Rapid Rotation 
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.


  1. 1.
    Baade, D.: A&A 222, 200 (1989)ADSGoogle Scholar
  2. 2.
    Balona, L.A.: MNRAS 252, 93 (1991)ADSGoogle Scholar
  3. 3.
    Balona, L.A., Cuypers, J., Marang, F.: A&AS 92, 533 (1992)ADSGoogle Scholar
  4. 4.
    Balona, L.A.: MNRAS 277, 1547 (1995)ADSGoogle Scholar
  5. 5.
    Cranmer, S.R.: ApJ 634, 585 (2005)ADSCrossRefGoogle Scholar
  6. 6.
    Cuypers, J., Balona, L.A., Marang, F.: A&AS 81, 151(1989)Google Scholar
  7. 7.
    Huat, A.-L., Hubert, A.-M., Baudin, F., et al.: A&A 506, 95 (2009)ADSCrossRefGoogle Scholar
  8. 8.
    Hubrig, S., Yudin, R.V., Pogodin, M., et al.: In: IV Reunion Anual Sociedad Chilena de Astronomia (SOCHIAS), 21 (2007)Google Scholar
  9. 9.
    Meilland, A., Millour, F., Stee, P., et al.: A&A 464, 73 (2007)ADSCrossRefGoogle Scholar
  10. 10.
    Rivinius, T., Baade, D., Štefl, S.: A&A 411, 229 (2003)ADSCrossRefGoogle Scholar
  11. 11.
    Silvester, J., Neiner, C., Henrichs, H.F., et al.: IAU Symp. 259, 391 (2009)ADSGoogle Scholar
  12. 12.
    Smith, M.A., Murakami, T., Ezuka, H., et al.: ApJ 481, 479 (1997)ADSCrossRefGoogle Scholar
  13. 13.
    Smith, M.A., Balona, L.A.: ApJ 640, 491 (2006)ADSCrossRefGoogle Scholar
  14. 14.
    Townsend, R.H.D., Owocki, S.P., Howarth, I.D.: MNRAS 350, 189 (2004)ADSCrossRefGoogle Scholar
  15. 15.
    Yudin, R., Hubrig, S., Pogodin, M., et al.: Stars: Be, Polarization, Magnetic Fields, IAU Symposium, vol. 259, p. 397 (2009)ADSGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  1. 1.South African Astronomical ObservatoryCape TownSouth Africa

Personalised recommendations