The New Magnetic White Dwarf PG 1031+234: Polarization and Field Structure at More than 500 Million Gauss
Abstract
PG 1031+234 is a newly discovered rotating, magnetic white dwarf. Its optical light is highly polarized, Pmax ≈ 6%, Vmax ≈ -12%, and strongly modulated on the 3 hr 24 minute rotation period. Optical and UV spectrophotometry reveal a spectrum of diffuse absorption features which match Zeeman calculations of hydrogen in fields 200 - 500×106G. The authors discuss the origin of polarized emission from a cold magnetized plasma and derive the polarization characteristics of the propagation eigenmodes. The results are used to model the polarization behavior of PG 1031+234 using crude approximations to the radiation physics and a straightforward geometric analysis. The observations can be reproduced by a rotating star containing an oblique centered dipole which is punctuated near its magnetic equator by a strong magnetic spot.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- October 1986
- DOI:
- 10.1086/164593
- Bibcode:
- 1986ApJ...309..218S
- Keywords:
-
- Magnetic Stars;
- Polarimetry;
- Stellar Magnetic Fields;
- Stellar Radiation;
- Stellar Spectrophotometry;
- White Dwarf Stars;
- Absorption Spectra;
- H Lines;
- Space Plasmas;
- Spectral Energy Distribution;
- Stellar Rotation;
- Zeeman Effect;
- Astrophysics;
- POLARIZATION;
- STARS: INDIVIDUAL ALPHANUMERIC: PG 1031;
- 234;
- STARS: MAGNETIC;
- STARS: WHITE DWARFS