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arXiv · 1811.03210

Evidence of enhanced magnetism in cool, polluted white dwarfs

Adela Kawka·Stephane Vennes·Lilia Ferrario·Ernst Paunzen
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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 (~5 200 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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Adela Kawka, Stephane Vennes, Lilia Ferrario, Ernst Paunzen. 2018-11-08. Evidence of enhanced magnetism in cool, polluted white dwarfs. https://doi.org/10.1093/mnras/sty3048

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