GJ 841B - The Second DQ White Dwarf with Polarized CH Molecular Bands

Abstract

We report a discovery of the circularly polarized CH $A^2\Delta -X^2\Pi$ and $B^2{\Sigma }^{-}-X^2\Pi$ molecular bands in the spectrum of the DQ white dwarf GJ 841B. This is only the second such object since the discovery of G99-37 in the 1970s. GJ 841B is also the first WD to unambiguously show polarization in the C_2 Swan bands. By modeling the intensity and circular polarization in the CH bands we determine the longitudinal magnetic field strength of 1.3 +- 0.5 MG and the temperature of 6100 +- 200 K in the absorbing region. We also present new observations of G99-37 and obtain estimates of the magnetic field strength 7.3 +- 0.3 MG and temperature 6200 +- 200 K, in good agreement with previous results.

10 pages, 3 figures

References in corpus (3)

• Magnetic White Dwarfs from the SDSS. The First Data Release
• Detailed Spectroscopic and Photometric Analysis of DQ White Dwarfs
• C_2 in Peculiar DQ White Dwarfs

Cited by in corpus (20)

• Magnetic White Dwarfs
• Know Your Neighborhood: A Detailed Model Atmosphere Analysis of Nearby White Dwarfs
• The binarity of the local white dwarf population
• Analysis of Helium-Rich White Dwarfs Polluted by Heavy Elements in the Gaia Era
• Magnetic fields in isolated and interacting white dwarfs
• A New Generation of Cool White Dwarf Atmosphere Models. IV. Revisiting the Spectral Evolution of Cool White Dwarfs
• New insight into the magnetism of degenerate stars from the analysis of a volume limited sample of white dwarfs
• The FORS1 catalogue of stellar magnetic field measurements
• Transient outburst events from tidally disrupted asteroids near white dwarfs
• Discovery of six new strongly magnetic white dwarfs in the 20 pc local population
• Searching for the weakest detectable magnetic fields in white dwarfs. Highly-sensitive measurements from first VLT and WHT surveys
• Discovery of a Sirius-like binary system with a very strongly magnetic white dwarf. Binarity among magnetic white dwarfs
• Spectropolarimetric observations of cool DQ white dwarfs
• Spectrophotometric analysis of magnetic white dwarf II: Helium-rich compositions
• Search for Higgs shifts in white dwarfs
• Optical polarimetry: Methods, Instruments and Calibration Techniques
• Clues to the origin and properties of magnetic white dwarfs
• Tracing Planetary Accretion in a 3 Gyr-old Hydrogen-Rich White Dwarf: The Extremely Polluted Atmosphere of LSPM J0207+3331
• Photometry of two DQ white dwarfs - search for spots
• Equation-of-motion coupled-cluster variants in combination with perturbative triples corrections in strong magnetic fields