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Related papers: The fraction of DA white dwarfs with kilo-Gauss ma…

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Current estimates for white dwarfs with fields in excess of 1MG are about 10%; according to our first high-precision circular-polarimetric study of 12 bright white dwarfs with the VLT (Aznar Cuadrado et al. 2004) this number increases up to…

Astrophysics · Physics 2007-05-23 S. Jordan , R. Aznar Cuadrado , R. Napiwotzki , H. M. Schmid , S. K. Solanki

Context: About 10% of white dwarfs have magnetic fields with strength in the range between about 10^5 and 3x10^8 G. It is not known whether the remaining white dwarfs are not magnetic, or if they have a magnetic field too weak to be…

Solar and Stellar Astrophysics · Physics 2015-06-11 J. D. Landstreet , S. Bagnulo , G. G. Valyavin , L. Fossati , S. Jordan , D. Monin , G. Wade

We have detected longitudinal magnetic fields between 2 and 4kG in three normal DA white dwarfs (WD0446-790, WD1105-048, WD2359$-$434) out of a sample of 12 by using optical spectropolarimetry done with the VLT Antu 8 m telescope equipped…

Astrophysics · Physics 2007-05-23 R. Aznar Cuadrado , S. Jordan , R. Napiwotzki , H. M. Schmid , S. K. Solanki , G. Mathys

We have detected longitudinal magnetic fields between 2 and 4 kG in three (WD 0446$-$790, WD 1105$-$048, WD 2359$-$434) out of a sample of 12 normal DA white dwarfs by using optical spectropolarimetry done with the VLT Antu 8 m telescope…

Astrophysics · Physics 2016-08-16 R. Aznar Cuadrado , S. Jordan , R. Napiwotzki , H. M. Schmid , S. K. Solanki , G. Mathys

We have carried out a re-analysis of polarimetric data of central stars of planetary nebulae, hot subdwarfs, and white dwarfs taken with FORS1 (FOcal Reducer and low dispersion Spectrograph) on the VLT (Very Large Telescope), and added a…

Solar and Stellar Astrophysics · Physics 2012-10-16 S. Jordan , S. Bagnulo , J. Landstreet , L. Fossati , G. G. Valyanin , D. Monin , G. A. Wade , K. Werner , S. J. O'Toole

Magnetic fields are present in roughly 10% of white dwarfs. These fields affect the structure and evolution of such stars, and may provide clues about their earlier evolution history. Particularly important for statistical studies is the…

Solar and Stellar Astrophysics · Physics 2019-03-06 John D. Landstreet , Stefano Bagnulo

Our knowledge of the magnetism in white dwarfs is based on an observational dataset that is biased in favour of stars with very strong magnetic fields. Most of the field measurements available in the literature have a relatively low…

Solar and Stellar Astrophysics · Physics 2018-10-24 Stefano Bagnulo , John D. Landstreet

We present new results of a survey for weak magnetic fields among DA white dwarfs with inclusion of some brighter hot subdwarf stars. We have detected variable circular polarization in the Halpha line of the hot subdwarf star Feige 34 (SP:…

Astrophysics · Physics 2008-11-26 G. Valyavin , S. Bagnulo , S. Fabrika , A. Reisenegger , G. A. Wade , Inwoo Han , D. Monin

Magnetic fields have been detected in several hundred white dwarfs, with strengths ranging from a few kG to several hundred MG. Only a few of the known fields have a mean magnetic field modulus below about 1 MG. We are searching for new…

Solar and Stellar Astrophysics · Physics 2016-06-29 J. D. Landstreet , S. Bagnulo , A. Martin , G. Valyavin

A significant fraction of white dwarfs harbour a magnetic field with strengths ranging from a few kG up to about 1000 MG. The fraction appears to depend on the specific class of white dwarfs being investigated and may hold some clues to the…

Solar and Stellar Astrophysics · Physics 2018-01-18 A. Kawka

Many stars evolve into magnetic white dwarfs, and observations may help to understand when the magnetic field appears at the stellar surface, if and how it evolves during the cooling phase, and what are the mechanisms that generate it.…

Solar and Stellar Astrophysics · Physics 2021-10-04 S. Bagnulo , J. D. Landstreet

We have conducted a survey of 61 southern white dwarfs searching for magnetic fields using Zeeman spectropolarimetry. Our objective is to obtain a magnetic field distribution for these objects and, in particular, to find white dwarfs with…

Astrophysics · Physics 2008-11-26 A. Kawka , S. Vennes , G. D. Schmidt , D. T. Wickramasinghe , R. Koch

To obtain a better statistics on the occurrence of magnetism among white dwarfs, we searched the spectra of the hydrogen atmosphere white dwarf stars (DAs) in the Data Release 7 of the Sloan Digital Sky Survey (SDSS) for Zeeman splittings…

Magnetic fields are detected in a few percent of white dwarfs. The number of such magnetic white dwarfs known is now some hundreds. Fields range in strength from a few kG to several hundred MG. Almost all the known magnetic white dwarfs…

Solar and Stellar Astrophysics · Physics 2017-11-22 J. D. Landstreet , S. Bagnulo , G. Valyavin , A. F. Valeev

We report the discovery of weak magnetic fields in three white dwarfs within the local 20pc volume (WD 0816-310, WD 1009-184, and WD 1532+129), and we confirm the magnetic nature of a fourth star (WD 2138-332) in which we had previously…

Solar and Stellar Astrophysics · Physics 2019-09-25 S. Bagnulo , J. D. Landstreet

We report the discovery of a new magnetic DA white dwarf (WD), WD0011-721, which is located within the very important 20pc volume-limited sample of the closest WDs to the Sun. This star has a mean field modulus <|B|> of 343 kG, and from the…

Solar and Stellar Astrophysics · Physics 2019-08-07 John D. Landstreet , Stefano Bagnulo

Around 10% of white dwarfs exhibit global magnetic structures with fields ranging from 1 kG to hundreds of MG. Recently, the first radiation magnetohydrodynamics simulations of the atmosphere of white dwarfs showed that convection should be…

We conducted a spectropolarimetic survey of 58 high proper-motion white dwarfs which achieved uncertainties of >2 kG in the Halpha line and >5 kG in the upper Balmer line series. The survey aimed at detecting low magnetic fields (< 100 kG)…

Solar and Stellar Astrophysics · Physics 2015-06-05 Adela Kawka , Stephane Vennes

We study the incidence of magnetism in white dwarfs from three large and well-observed samples of hot, cool, and nearby white dwarfs in order to test whether the fraction of magnetic degenerates is biased, and whether it varies with…

Astrophysics · Physics 2009-11-07 James Liebert , P. Bergeron , J. B. Holberg

A significant fraction of white dwarfs possess a magnetic field with strengths ranging from a few kG up to about 1000 MG. However, the incidence of magnetism varies when the white dwarf population is broken down into different spectral…

Solar and Stellar Astrophysics · Physics 2020-10-14 Adela Kawka
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