Comments on the magnetic field structure of the star CU Virginis

¹ Special Astrophysical Observatory of Russian AS, Nizhnij Arkhyz 357147, Russia
² Isaac Newton Institute of Chile, SAO Branch
³ 14471 Potsdam, Gontardstr 130, Germany e-mail: Ewald-Gerth@t-online.de

Corresponding author: Yu. V. Glagolevskij, glagol@sao.ru

Received: 4 October 2001
Accepted: 8 November 2001

Abstract

The model of the magnetic field structure of the CP2 star CU Vir (HD 124224) constructed by the method of “magnetic charge distribution" (MCD-method) has shown that it is consistent with the model of a displaced dipole. The displacement from the center of the star to the negative monopole is of the radius, the inclination angle of the dipole axis to the rotational axis is , and the field strength at the poles amounts to  kG and  kG. The mean surface magnetic field varies within 1.2–3.2 kG. The dipole axis points away from the zero meridian by an angle of . Using the MCD-method we derived the distribution of the field intensity over the surface, which has been compared to the distribution of the chemical elements He and Si, taken from literature. Silicon has turned out to concentrate around the strong negative magnetic pole, whereas helium concentrates in the region of the weak positive pole, where the orientation of magnetic lines of force is mostly vertical. The presence of a double silicon spot suggests a more complex magnetic field structure than the dipolar one, however, the small number of data makes it impossible so far to confirm such an assumption.