  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 a $M\sim 1.1\,M_\odot$
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 in a 1d time-scale, 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 at least 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.
