Astronomy and Astrophysics – Astrophysics
Scientific paper
2008-04-19
Astronomy and Astrophysics
Astrophysics
11 figures
Scientific paper
10.1086/589234
We present and interpret new spectropolarimetric observations of the magnetic white dwarf WD 1953-011. Circular polarization and intensity spectra of the H$\alpha$ spectral line demonstrate the presence of two-component magnetic field in the photosphere of this star. The geometry consists of a weak, large scale component, and a strong, localized component. Analyzing the rotationally modulated low-field component, we establish a rotation period $P_{rot} = 1.4480 \pm 0.0001$ days. Modeling the measured magnetic observables, we find that the low-field component can be described by the superposition of a dipole and quadrupole. According to the best-fit model, the inclination of the stellar rotation axis with respect to the line of sight is $i \approx 20^\circ$, and the angle between the rotation axis and the dipolar axis is $\beta \approx 10^\circ$. The dipole strength at the pole is about 180 kG, and the quadrupolar strength is about 230 kG. These data suggest a fossil origin of the low-field component. In contrast, the strong-field component exhibits a peculiar, localized structure (``magnetic spot'') that confirms the conclusions of Maxted and co-workers. The mean field modulus of the spot ($|B_{spot}| = 520 \pm 7$ kG) together with its variable longitudinal magnetic field having a maximum of about +400 kG make it difficult to describe it naturally as a high-order component of the star's global poloidal field. Instead, we suggest that the observed strong-field region has a geometry similar to a magnetic flux tube.
Bagnulo Stefano
Burenkov Alexander
Han Inwoo
Landstreet John Darlington
Szeifert Thomas
No associations
LandOfFree
The pecular magnetic field morphology of the white dwarf WD 1953-011: evidence for a large-scale magnetic flux tube? does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The pecular magnetic field morphology of the white dwarf WD 1953-011: evidence for a large-scale magnetic flux tube?, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The pecular magnetic field morphology of the white dwarf WD 1953-011: evidence for a large-scale magnetic flux tube? will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-651725