Discovery of magnetic fields in five DC white dwarfs
Additional information
Authors
Berdyugin A. V. .,
Piirola V.,
Bagnulo S.,
Landstreet J. D. .,
Berdyugina S.
Type
Journal Article
Year
2023
Language
English
Abstract
About half of white dwarfs (WDs) evolve to the DC state as they cool;the others become DQ or (temporarily?) DZ WDs. The recentmagnetic survey of the local 20 pc volume has established a highfrequency of magnetic fields among WDs older than 2-3 Gyr,demonstrating that in low- and average-mass WDs, the effects ofmagnetism become more common as they age, and the fields onaverage become stronger. However, the available statistics ofWDs older than about 5 Gyr do not clearly establish how fieldsevolve beyond this age. We are carrying out a survey to clarifythe occurrence of magnetism in DC-type WDs in order to betterunderstand this late evolution. We use broadband filterpolarimetry, arguably the most efficient way to detect magneticfields in featureless WDs via continuum circular polarization.Here we report the discovery of a magnetic field in five DC WDs(of 23 observed), almost doubling the total sample of knownmagnetic WDs belonging to the DC spectral class.
Journal
Astronomy and Astrophysics
Volume
670
Start page number
A2
