相关论文: On the incidence of weak magnetic fields in DA whi…
Weak magnetic field has been searched for on only a small number of white dwarfs. Current estimates for white dwarfs with fields in excess of 1MG are about 10%; according to previous studies this number increases up to about 25% in the kG…
We have detected longitudinal magnetic fields between 2 and 4 kG in three (WD 0446$-$790, WD 1105$-$048, WD 2359$-$434) out of a sample of 12 normal DA white dwarfs by using optical spectropolarimetry done with the VLT Antu 8 m telescope…
We have detected longitudinal magnetic fields between 2 and 4kG in three normal DA white dwarfs (WD0446-790, WD1105-048, WD2359$-$434) out of a sample of 12 by using optical spectropolarimetry done with the VLT Antu 8 m telescope equipped…
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…
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…
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:…
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…
Searches for magnetic fields in white dwarfs have clarified both the frequency of occurrence and the global structure of the fields found down to field strengths of the order of 500 kG. Below this level, the situation is still very unclear.…
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…
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…
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…
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…
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.…
The sample of white dwarfs included in the local 20 pc volume documents, fairly accurately, the total production of white dwarfs over roughly 10 Gyr of stellar evolution in this part of the Milky Way Galaxy. In this sample, we have been…
Little is known about the incidence of magnetic fields among the coolest white dwarfs. Their spectra usually do not exhibit any absorption lines as the bound-bound opacities of hydrogen and helium are vanishingly small. Probing these stars…
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…
Detection of magnetic fields has been reported in several sdO and sdB stars. Recent literature has cast doubts on the reliability of most of these detections. We revisit data previously published in the literature, and we present new…
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)…
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…