Discovery of kilogauss magnetic fields in three DA white dwarfs
We have detected longitudinal magnetic fields between 2 and 4 kG in three (WD0446−790, WD1105−048, WD2359−434) out of a sample of 12 normal DA white dwarfs by using optical spectropolarimetry done with the VLT Antu 8 m telescope equipped with FORS1.With the exception of 40 Eri B (4 kG) these are the first positive detections of magnetic fields in white dwarfs below 30 kG. Although suspected, it was not clear whether a significant fraction of white dwarfs contain magnetic fields at this level. These fields may be explained as relics from magnetic fields in the main-sequence progenitors considerably enhanced by magnetic flux conservation during the shrinkage of the core. A detection rate of 25% (3/12) may indicate now for the first time that a substantial fraction of white dwarfs have a weak magnetic field. This result, if confirmed by future observations, would form a cornerstone for our understanding of the evolution of stellar magnetic fields.
Item Type | Article |
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Additional information | Original article can be found at: http://www.aanda.org/--Copyright The European Southern Observatory --DOI : 10.1051/0004-6361:20040355 |
Date Deposited | 15 May 2025 11:56 |
Last Modified | 30 May 2025 23:41 |
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