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A New Technique for the Measurement of Stellar Magnetic Fields: First Results

  • S. K. Solanki
  • G. Mathys
Part of the Astrophysics and Space Science Library book series (ASSL, volume 143)

Abstract

A technique for determining strengths and filling factors of stellar magnetic fields is presented. It is based on a statistical analysis of a large number of unblended Fe I lines and was first introduced by Stenflo and Lindegren (1977). It has been tested in solar active regions and is now applied to late type stars. First results of an analysis of high S/N spectra of three stars are presented and compared to previous measurements. One advantage of the method is that unlike the often used Robinson technique (Robinson, 1980) it is relatively insensitive to the presence of small blends. Finally, the statistical method in principle allows us to decide whether the observed field is concentrated in stellar spots or in plages. Preliminary results for HR 1084 suggest that the field is in the form of plages.

Keywords

Filling Factor Zeeman Splitting Solar Active Region Solar Data Late Type Star 
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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References

  1. Bonsack, W.K., Simon, T.: 1983, in Solar and Stellar Magnetic Fields: Origins and Coronal Effects, J.O. Stenflo (Ed.), IAU Symp. 102, 35Google Scholar
  2. Borra, E.F., Edwards, G., Mayor, M.: 1984, Astrophys. J. 284, 211ADSCrossRefGoogle Scholar
  3. Brandt, P.N., Solanki, S.K.: 1987a, in Proc. Workshop on the Role of Fine-Scale Magnetic Fields on the Structure of the Solar Atmosphere, Tenerife, 6–12 Oct. 1986, in pressGoogle Scholar
  4. Brandt, P.N., Solanki, S.K.: 1987b, Astron. Astrophys. to be submittedGoogle Scholar
  5. Giampapa, M.S., Golub, L., Worden, S.P: 1983, Astrophys. J. 268, L121ADSCrossRefGoogle Scholar
  6. Gray, D.F.: 1984, Astrophys. J. 277, 640ADSCrossRefGoogle Scholar
  7. Grossmann-Doerth, U., Pahlke, K.-D., Schiissler, M.: 1987, Astron. Astrophys. 176, 139ADSGoogle Scholar
  8. Kurucz, R.L., Hartmann, L.: 1984, SAO Preprint, No. 2015Google Scholar
  9. Landi Degl’Innocenti, E.: 1982, Solar Phys. 77, 285ADSCrossRefGoogle Scholar
  10. Landi Degl’Innocenti, E.: 1985, Solar Phys. 99, 1ADSCrossRefGoogle Scholar
  11. Marcy, G.W.: 1984, Astrophys. J. 276, 286ADSCrossRefGoogle Scholar
  12. Mathys, G., Solanki, S.K.: 1987, in The Impact of Very High S/N Spectroscopy on Stellar Physics, IAU Symp. 132, in pressGoogle Scholar
  13. Mathys, G., Stenflo, J.O.: 1986, Astron. Astrophys. 168, 184ADSGoogle Scholar
  14. Mathys, G., Stenflo, J.O.: 1987a, Astron. Astrophys. 171, 368ADSGoogle Scholar
  15. Mathys, G., Stenflo, J.O.: 1987b, Astron. Astrophys. Suppl. Ser. 67, 557ADSGoogle Scholar
  16. Mathys, G., Stenflo, J.O.: 1987c, in The Impact of Very High S/N Spectroscopy on Stellar Physics, IAU Symp. 132, in pressGoogle Scholar
  17. Robinson, R.D.: 1980, Astrophys. J. 239, 961ADSCrossRefGoogle Scholar
  18. Robinson, R.D., Worden, S.P., Harvey, J.W.: 1980, Astrophys. J. 236, L155ADSCrossRefGoogle Scholar
  19. Saar, S.H.: 1987, Ph.D. Thesis, JILA, Boulder, COGoogle Scholar
  20. Saar, S.H., Linsky, J.L., Beckers, J.M.: 1986, Astrophys. J. 302, 777ADSCrossRefGoogle Scholar
  21. Schüssler, M., Solanki, S.K.: 1987, Astron. Astrophys. in pressGoogle Scholar
  22. Solanki, S.K., Stenflo, J.O.: 1984, Astron. Astrophys. 140, 185ADSGoogle Scholar
  23. Stenflo, J.O., Lindegren, L.: 1977, Astron. Astrophys. 59, 367ADSGoogle Scholar

Copyright information

© Kluwer Academic Publishers 1988

Authors and Affiliations

  • S. K. Solanki
    • 1
  • G. Mathys
    • 2
  1. 1.Institute of AstronomyETH-ZentrumZürichSwitzerland
  2. 2.Geneva ObservatorySauvernySwitzerland

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