@Article{SchreiberBelGanParZor:2021:OrEvMa,
               author = "Schreiber, Matthias R. and Belloni, Diogo Teixeira and Gansicke, 
                         Boris T. and Parsons, Steven G. and Zorotovic, Monica",
          affiliation = "{Universidad Tecnologica Federico Santa Maria} and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)} and {University Warwick} 
                         and {University Sheffield} and {Universidad Valparaiso}",
                title = "The origin and evolution of magnetic white dwarfs in close binary 
                         stars",
              journal = "Nature Astronomy",
                 year = "2021",
               volume = "5",
               number = "7",
                pages = "648--654",
                month = "July",
             abstract = "The origin of magnetic fields in white dwarfs remains a 
                         fundamental unresolved problem in stellar astrophysics. In 
                         particular, the very different fractions of strongly (more than 
                         about a megagauss) magnetic white dwarfs in evolutionarily linked 
                         populations of close white dwarf binary stars cannot be reproduced 
                         by any scenario suggested so far. Strongly magnetic white dwarfs 
                         are absent among detached white dwarf binary stars that are 
                         younger than approximately a billion years. In contrast, of 
                         cataclysmic variables (semi-detached binary star systems that 
                         contain a white dwarf) in which the white dwarf accretes from a 
                         low-mass star companion, more than a third host a strongly 
                         magnetic white dwarf(1). Here we present binary star evolutionary 
                         models that include the spin evolution of accreting white dwarfs 
                         and crystallization of their cores, as well as magnetic field 
                         interactions between the stars. We show that a crystallization- 
                         and rotation-driven dynamo similar to those working in planets and 
                         low-mass stars(2) can generate strong magnetic fields in the white 
                         dwarfs in cataclysmic variables, which explains their large 
                         fraction among the observed population. When the magnetic field 
                         generated in the white dwarf connects with that of the secondary 
                         star in the binary system, synchronization torques and reduced 
                         angular momentum loss cause the binary to detach for a relatively 
                         short period of time. The few known strongly magnetic white dwarfs 
                         in detached binaries, such as AR Scorpii(3), are in this detached 
                         phase. The complex evolutionary dance of the strongly magnetic 
                         white dwarf in a compact binary system can be effectively modelled 
                         by considering spin evolution, core crystallization and a 
                         rotation-driven dynamo similar to that in planets and low-mass 
                         stars.",
                  doi = "10.1038/s41550-021-01346-8",
                  url = "http://dx.doi.org/10.1038/s41550-021-01346-8",
                 issn = "2397-3366",
             language = "en",
           targetfile = "schreiber2021.pdf",
        urlaccessdate = "11 maio 2024"
}