Hostname: page-component-89b8bd64d-mmrw7 Total loading time: 0 Render date: 2026-05-09T12:49:06.681Z Has data issue: false hasContentIssue false
  • English
  • Français

Unraveling the variability of σ Ori E

Published online by Cambridge University Press:  23 January 2015

M. E. Oksala ,
O. Kochukhov ,
J. Krtička ,
M. Prvák  and
Z. Mikulášek
M. E. Oksala
Affiliation:
Astronomical Institute, Academy of Sciences of the Czech Republic, Fricova 298, 251 65 Ondřejov, Czech Republic email: meo@udel.edu
O. Kochukhov
Affiliation:
Department of Physics and Astronomy, Uppsala University, Box 516, Uppsala 75120, Sweden
J. Krtička
Affiliation:
Institute of Theoretical Physics and Astrophysics, Masaryk University, 611 37 Brno, Czech Republic
M. Prvák
Affiliation:
Institute of Theoretical Physics and Astrophysics, Masaryk University, 611 37 Brno, Czech Republic
Z. Mikulášek
Affiliation:
Institute of Theoretical Physics and Astrophysics, Masaryk University, 611 37 Brno, Czech Republic
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the 'Save PDF' action button.

σ Ori E (HD 37479) is the prototypical helium-strong star shown to harbor a strong magnetic field, as well as a magnetosphere consisting of two clouds of plasma. The observed optical (ubvy) light curve of σ Ori E is dominated by eclipse features due to circumstellar material, however, there remain additional features unexplained by the Rigidly Rotating Magnetosphere (RRM) model of Townsend & Owocki (2005). Using the technique of magnetic Doppler imaging (MDI), spectropolarimetric observations of σ Ori E are used to produce maps of both the magnetic field topology and various elemental abundance distributions. We also present an analysis utilizing these computed MDI maps in conjunction with non-local thermodynamical equilibrium TLUSTY models to study the optical brightness variability of this star arising from surface inhomogeneities. It has been suggested that this physical phenomena may be responsible for the light curve inconsistencies between the model and observations.

Keywords

stars: magnetic fieldsstars: rotationstars: early-typestars: circumstellar matterstars: individual: HD 37479techniques: spectroscopictechniques: polarimetricultraviolet: stars

References

Hesser, J. E., Ugarte, P. P., & Moreno, H. 1977, ApJ (Letters) 216, L31CrossRefGoogle Scholar
Hubeny, I. & Lanz, T. 1995, ApJ 439, 875CrossRefGoogle Scholar
Kochukhov, O., Mantere, M. J., Hackman, T., & Ilyin, I. 2013, A&A 550, A84Google Scholar
Kochukhov, O., Wade, G. A., & Shulyak, D. 2012, MNRAS 421, 3004Google Scholar
Krtička, J., Mikulášek, Z., Zverko, J. & Žižńovský, J. 2007, A&A 470, 1089Google Scholar
Lanz, T. & Hubeny, I. 2007, ApJS 169, 83Google Scholar
Mihalas, D. 1978, Stellar atmospheres, 2nd edition, W. H. Freeman and Co., San FransiscoGoogle Scholar
Oksala, M. E., Wade, G. A., Townsend, R. H. D., et al. 2012, MNRAS 419, 959CrossRefGoogle Scholar
Piskunov, N. & Kochukhov, O. 2002, A&A 381, 736Google Scholar
Townsend, R. H. D., Oksala, M. E., Cohen, D. H., Owocki, S. P., & ud-Doula, A. 2010, ApJ (Letters) 714, L318Google Scholar
Townsend, R. H. D. & Owocki, S. P. 2005, MNRAS 357, 251Google Scholar
Townsend, R. H. D., Owocki, S. P., & Groote, D. 2005, ApJ (Letters) 630, L81CrossRefGoogle Scholar
Townsend, R. H. D., Rivinius, T., Rowe, J. F., et al. 2013, ApJ 769, 33Google Scholar
Wade, G. A., Alecian, E., Bohlender, D. A., et al. 2011, in Neiner, C., Wade, G., Meynet, G., & Peters, G. (eds.), IAU Symposium, Vol. 272 of IAU Symposium, pp 118–123Google Scholar