Studies of Features of Evolution of Highly Magnetized White Dwarfs and Some Other Stars under Conditions of Magnetically Induced Suppression of Convective Energy Removal. II. Modeling

Abstract

We present a study of the influence of magnetically induced control of external convection in stars of different types, in particular white dwarfs, on their thermal evolution. In the work preceding this study, we argued that for the cooling down white dwarf stars that have exhausted the sources of thermonuclear combustion, cessation of convection by a magnetic field significantly slows down their cooling. To test this asertion, we performed an observational program to search for new highly magnetized white dwarfs. The program is described in detail in the same issue of the journal. Our observations, together with the observations of other researchers, allowed us to construct the observed luminosity function of strongly magnetized white dwarfs with stopped convection and compare it with the well-known similar luminosity function of white dwarfs with weak fields that allow effective convective heat removal from their insides. As a result of the model analysis of these functions, the hypothesis that strongly magnetized white dwarfs cool down slower than weakly magnetic ones is confirmed. The article also qualitatively examines the effect of magnetic braking of convection in solar-type stars and cool M-dwarf stars of the Main Sequence on the periodicity of their radiation activity. The geophysical aspect of the problem and the practical application of magnetic field control of the heat removal in electrically conductive media are discussed.