Evidence of enhanced magnetism in cool, polluted white dwarfs
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...
| Main Authors: | , , , |
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| Format: | Journal Article |
| Language: | English |
| Published: |
OXFORD UNIV PRESS
2019
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| Subjects: | |
| Online Access: | http://dx.doi.org/10.1093/mnras/sty3048 http://hdl.handle.net/20.500.11937/80398 |
| Summary: | 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. |
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