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Suppression of cooling by strong magnetic fields in white dwarf stars

Russian version

    Astronomers of the SAO together with an international group of scientists have proposed an explanation to the long-standing mystery of why magnetic fields are more common amongst cool white dwarf stars than amongst young and hotter ones. In the framework of theoretical analysis of observations (including observations from the BTA) the authors have shown that strongest magnetic fields are sufficient to suppress convection over the entire surface in cool magnetic white dwarfs, which inhibits their cooling evolution relative to weakly magnetic and non-magnetic ones. As the result magnetic white dwarfs demonstrate excess in their frequencies in the temperature range below 14000K. The authors also show that the strongly magnetic white dwarfs are of the oldest stars of the Galaxy originated from intermediate-mass relic stars.
G.Valyavin, D.Shulyak, G.A.Wade, K.Antornyuk and 16 co-authors, 2014, Nature, doi:10.1038/nature13836

Contact - Gennady Valyavin
Fig.1. Computer visualization of the reconstructed magnetic-field and temperature (brightness) distribution on the surface of the magnetic dwarf WD1953-011