文章基本信息

标题：Discovery of a Sirius-like binary system with a very strongly magnetic white dwarf
其他标题：Binarity among magnetic white dwarfs
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作者：John D. Landstreet ; Stefano Bagnulo
期刊名称：Astronomy & Astrophysics
印刷版ISSN：0004-6361
电子版ISSN：1432-0746
出版年度：2020
卷号：634
页码：1-5
DOI：10.1051/0004-6361/201937301
语种：English
出版社：EDP Sciences
摘要：Non-interacting binary systems containing a magnetic white dwarf and a main-sequence star are considered extremely rare, perhaps non-existent. In the course of a search of magnetic fields in high-mass white dwarfs we have discovered a Sirius-like wide binary system composed of a main-sequence G0 star and anM ∼ 1.1 M⊙white dwarf with a huge (hundreds of MG) magnetic field. This star, WDS J03038+0608B, shows a circular polarisation amplitude of 5% in the continuum, with no evidence of variability on a 1 d timescale, little or no linear polarisation in the blue part of the spectrum, and about 2% linear polarisation in the red part of the optical spectrum. A search in the literature reveals the existence of four more binary systems that include a magnetic white dwarf and a non-degenerate companion; three such systems passed unremarked in previous studies. We estimate that up to a few percent of magnetic white dwarfs may be found to occur in wide binary pairs. However, at least four of the five known binary systems with a magnetic white dwarf are too widely separated to be expected to evolve into systems experiencing Roche-lobe overflow, and cannot be considered as progenitors of magnetic cataclysmic variable (AM Her and DQ Her) systems.
关键词：enstars: magnetic fieldwhite dwarfsbinaries: visualstars: individual: WD0301+059