Evidence of enhanced magnetism in cool, polluted white dwarfs
Abstract
We report the discovery of a new, polluted, magnetic white dwarf in the Luyten survey of high-proper motion stars. High-dispersion spectra of NLTT 7547 reveal a complex heavy element line spectrum in a cool (≈5200 K) hydrogen-dominated atmosphere showing the effect of a surface averaged field of 163 kG, consistent with a 240 kG centred dipole, although the actual field structure remains uncertain. The abundance pattern shows the effect of accreted material with a distinct magnesium-rich flavour. Combined with earlier identifications, this discovery supports a correlation between the incidence of magnetism in cool white dwarfs and their contamination by heavy elements.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- February 2019
- DOI:
- 10.1093/mnras/sty3048
- arXiv:
- arXiv:1811.03210
- Bibcode:
- 2019MNRAS.482.5201K
- Keywords:
-
- stars: abundances;
- stars: individual: NLTT 7547;
- stars: magnetic field;
- white dwarfs;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- Accepted for publication in MNRAS