New topological approach to the problem of solar flare trigger

The analysis of the structure of solar magnetic field formed by two coplanar but non-colinear bipolar spot pairs is presented. The analysis of topological peculiarities of magnetic fields shows that a three-dimensional generalization of the line of X-type neutral points, namely separator, can appear and vanish with the evolution of sunspots arrangement. A three-dimensional magnetic field neutral line can exist even if the sunspots do not lie on a straight line. An isolated neutral point of magnetic field can appear on the separator above the plane of location of sunspots, and a small change of sunspots arrangement causes a great displacement of neutral point along the separator