Search for the radial magnetic-field gradient in the CP star α 2 CVn
Abstract
The possibility of investigating the vertical structure of the magnetic field in chemically peculiar main-sequence stars is discussed. The nonuniform distribution of chemical elements over the surface complicates the problem substantially. The most efficient measurements are shown to be those of the longitudinal field components based on spectral lines with wavelengths longer and shorter than 3646 Å (shortward and longward of the Balmer jump), which form at different optical depths in the atmosphere. Various methodological problems are addressed that must be overcome in order to accomplish the task. The brightest magnetic star α 2 CVn is observed with the echelle spectrometer equipped with an Uppsala CCD chip. New observations corroborate our previous result: the longitudinal component of the magnetic field B e of the α 2 CVn star increases with depth by about 30% over the atmosphere thickness scale.
- Publication:
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Astrophysical Bulletin
- Pub Date:
- March 2007
- DOI:
- 10.1134/S1990341307010038
- Bibcode:
- 2007AstBu..62...26R
- Keywords:
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- 97.30.Fi