Searching for magnetic fields in featureless white dwarfs with the DIPOL-UF polarimeter at the Nordic Optical Telescope

被引:1
|
作者
Berdyugin, A. [1 ]
Landstreet, J. D. [2 ,3 ]
Bagnulo, S. [2 ]
Piirola, V. [1 ]
Berdyugina, S. V. [4 ,5 ,6 ]
机构
[1] Univ Turku, Dept Phys & Astron, FI-20014 Turku, Finland
[2] Armagh Observ & Planetarium, Coll Hill, Armagh BT61 9DG, North Ireland
[3] Univ Western Ontario, London, ON N6A 3K7, Canada
[4] Univ Svizzera Italiana, IRSOL Ist Ric Solari Aldo & Cele Dacco, Fac Informat, Via Patocchi 57, Locarno, Switzerland
[5] Univ Svizzera Italiana, Euler Inst, Fac Informat, Via Santa 1, CH-6962 Lugano, Switzerland
[6] Inst Sonnenphys KIS, Georges Kohler Allee 401A, D-79110 Freiburg, Germany
基金
加拿大自然科学与工程研究理事会;
关键词
techniques: polarimetric; stars: magnetic field; white dwarfs; CIRCULAR-POLARIZATION; DISCOVERY; DEGENERATE; COOL; PC; SPECTRUM; CATALOG; SAMPLE; STARS;
D O I
10.1051/0004-6361/202450527
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
About 20% of the white dwarfs possess a magnetic field that may be detected by the splitting and/or polarization of their spectral lines. As they cool, the effective temperatures of the white dwarfs become so low that no spectral lines can be seen in the visible wavelength range. If their atmospheres are not polluted by the debris of a planetary system, these cool white dwarfs have featureless optical spectra. Until quite recently, very little was known about the incidence of magnetic fields in these objects. However, when observed with polarimetric techniques, a significant number of featureless white dwarfs reveal strong magnetic fields in their optical continuum spectra. Measuring the occurrence rate and strength of magnetic fields in old white dwarfs may help us to understand how these fields are generated and evolve. We report the results of an ongoing survey of cool white dwarfs with the high-precision broad-band polarimeter DIPOL-UF, which is deployed at the Nordic Optical Telescope on La Palma, Spain. This survey has led to the firm discovery of 13 new cool magnetic white dwarfs in the solar neighborhood so far, including six new detections that we report in this paper.
引用
收藏
页数:6
相关论文
共 1 条
  • [1] Searching for the weakest detectable magnetic fields in white dwarfs Highly-sensitive measurements from first VLT and WHT surveys
    Bagnulo, S.
    Landstreet, J. D.
    ASTRONOMY & ASTROPHYSICS, 2018, 618