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Modelling of the Magnetic Configuration of CP Stars from Polarimetric Observations

Published online by Cambridge University Press:  14 August 2015

M. Landolfi*
Affiliation:
Osservatorio di Arcetri1-50125 Firenze, Italia

Extract

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The observational quantities commonly used to study the magnetic field of CP stars – the mean field modulus and the mean longitudinal field, as well as the ‘mean asymmetry of the longitudinal field’ and the ‘mean quadratic field’ recently introduced by Mathys (1995a,b) – are based either on the Stokes parameter / or on the Stokes parameter V. However, a complete description of polarized radiation requires the knowledge of the full Stokes vector: in other words, we should expect that useful information is also contained in linear polarization (the Stokes parameters Q and U); or rather we should expect the information contained in (Q, U) and in V to be complementary, since linear and circular polarization are basically related to the transverse and the longitudinal component of the magnetic field, respectively.

Type
II. Joint Discussions
Copyright
Copyright © Kluwer 1998

References

Bagnulo, S., Landi Degl’Innocenti, E., Landolfi, M. and Leroy, J.L. (1995) Linear polarimetry of Ap stars III. A diagnostic method for the magnetic structure of rotating stars, Astron. Astrophys. 295, pp. 459470 Google Scholar
Borra, E.F. and Vaughan, A.H. (1976) Observations of the transverse Zeeman effect in the magnetic star Beta Coronae Borealis: Evidence for the oblique rotator model, Astrophys. J. 210, pp. L145L147 Google Scholar
Kemp, J.C. and Wolstencroft, R.D. (1974) The intrinsic linear polarization of 53 Camelopardalis and α1 Canum Venaticorum, Mon. Not. Roy. Astron. Soc. 166, pp. 118 Google Scholar
Landolfi, M., Landi Degl’Innocenti, E., Landi Degl’Innocenti, M. and Leroy, J.L. (1993) Linear polarimetry of Ap stars I. A simple canonical model, Astron. Astrophys. 272, pp. 285298 Google Scholar
Landolfi, M-, Bagnulo, S., Landi Degl’Innocenti, M., Landi Degl’Innocenti, E. and Leroy, J.L. (1997) Constraints on the magnetic configuration of Ap stars from simple features of observed quantities, Astron. Astrophys. 322, pp. 197201 Google Scholar
Leroy, J.L. (1962) Contributions a l’étude de la polarisation de la lumière solaire, Ann. Astrophys. 25, pp. 127164 Google Scholar
Leroy, J.L. (1995) Linear polarimetry of Ap stars V. A general catalogue of measurements, Astron. Astrophys. Suppl. 114, pp. 79104 Google Scholar
Leroy, J.L., Landolfi, M. and Landi Degl’Innocenti, E. (1996) Linear polarimetry of Ap stars VI. A modified dipolar model consistent with the observations, Astron. Astrophys. 311, pp. 513522 Google Scholar
Mathys, G. (1995a) Spectropolarimetry of magnetic stars IV. The crossover effect, Astron. Astrophys. 293, pp. 733745 Google Scholar
Mathys, G. (1995b) Spectropolarimetry of magnetic stars V. The mean quadratic magnetic field, Astron. Astrophys. 293, pp. 746763 Google Scholar
Piirola, V. and Tuominen, I. (1981) The intrinsic linear polarization of the magnetic variable HD 71866, in: CP stars of the upper main sequence, 23rd International Conference on Astrophysics, Liège, Université de Liège, pp. 283288 Google Scholar