ИСТИНА

We discuss briefly the problem of extrapolation of the magnetic fields of active regions (AR) into the corona and estimate the maximal energy of flares that can occur in a given AR on the Sun. The magnetic field energy E is computed directly both from the non-linear force free field (NLFFF) extrapolation, and from the virial theorem. In the frameworks of a simple model we determine the free energy, Ef = E–Epot (where Epot – is the energy of the potential field), that is deposited in the lowest corona and can be expended further on formation of non-stationary processes. From data on the full vector of the magnetic field obtained with SDO and Hinode we estimate the maximal energy of flares on the contemporary Sun – 3•1032 ergs. The analysis of new Kepler data shows that G stars similar to the young Sun, sometimes demonstrate superflare with the total energy up to 1035 ergs. Spectropolarimetric observations and indirect evidences on local magnetic fields on G dwarf stars agree with our knowledge on distribution of the magnetic fields on the Sun. Available data on the magnetic fields for G stars indicate that the flare energy does not exceed 1035 ergs. Hence superflares with energies up to 1035 ergs can not be associated with the energy deposit above the chromosphere and its subsequent release. The nature of these superflares is not analogical to the solar flares. One can only assume that such superflares can be caused by an ejection of the magnetized plasma from sub-photospheric layers.