Magnetic Field And Chemical Anomalies of Ap Stars

1976 ◽  
Vol 32 ◽  
pp. 43-48
Author(s):  
A.Z. Dolginov
Keyword(s):  
Magnetic Field ◽  
Liquid Core ◽  
Close Binaries ◽  
Poloidal Magnetic Field ◽  
Stellar Matter ◽  
The Earth ◽  
Chemical Anomalies ◽  
Ap Stars ◽  
The Magnetic Field ◽  
Chemical Anomaly

SummaryIt is shown that owing to the “battery” effect the spatial nonuniform helium distribution in Ap stars causes a toroidal magnetic field of about 103- 104gauss. Possible circulation of stellar matter in this field produce a poloidal magnetic field of the same order as the toroidal one even if the velocities of circulation are about 10-4-10-5cm/s. The chemical anomaly in turn is supported and amplified by the magnetic field. It is pointed out that the “battery” effect is likely to take place in the liquid core of the earth and in components of close binaries if they are nonuniformly heated by their companions.

scholarly journals Broadband Linear Polarization in Ap Stars

1993 ◽  
Vol 138 ◽  
pp. 305-309
Author(s):  
Marco Landolfi ◽  
Egidio Landi Degl’Innocenti ◽  
Maurizio Landi Degl’Innocenti ◽  
Jean-Louis Leroy ◽  
Stefano Bagnulo
Keyword(s):  
Magnetic Field ◽  
Circular Polarization ◽  
Linear Polarization ◽  
Rotation Axis ◽  
Spectral Lines ◽  
Line Of Sight ◽  
Long Time ◽  
Rotating Star ◽  
Ap Stars ◽  
The Magnetic Field

AbstractBroadband linear polarization in the spectra of Ap stars is believed to be due to differential saturation between σ and π Zeeman components in spectral lines. This mechanism has been known for a long time to be the main agent of a similar phenomenon observed in sunspots. Since this phenomenon has been carefully calibrated in the solar case, it can be confidently used to deduce the magnetic field of Ap stars.Given the magnetic configuration of a rotating star, it is possible to deduce the broadband polarization at any phase. Calculations performed for the oblique dipole model show that the resulting polarization diagrams are very sensitive to the values of i (the angle between the rotation axis and the line of sight) and β (the angle between the rotation and magnetic axes). The dependence on i and β is such that the four-fold ambiguity typical of the circular polarization observations ((i,β), (β,i), (π-i,π-β), (π-β,π-i)) can be removed.

scholarly journals On the differential system govering flows in magnetic field with data inLp

1998 ◽  
Vol 21 (2) ◽  
pp. 299-305 ◽  
Author(s):  
Fengxin Chen ◽  
Ping Wang ◽  
Chaoshun Qu
Keyword(s):  
Magnetic Field ◽  
Initial Data ◽  
Boundary Conditions ◽  
Differential System ◽  
Existence And Uniqueness ◽  
Mhd Equations ◽  
The Earth ◽  
Initial And Boundary Conditions ◽  
Time Existence ◽  
The Magnetic Field

In this paper we study the system governing flows in the magnetic field within the earth. The system is similar to the magnetohydrodynamic (MHD) equations. For initial data in spaceLp, we obtained the local in time existence and uniqueness ofweak solutions of the system subject to appropriate initial and boundary conditions.

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