THE FILAMENTARY STRUCTURE IN SUNSPOTS

The present paper is intended to discuss the non-axisymmetric filamentary structure in sunspots.Given the geometric shape of the field lines,analytic solutions are presented for both zeroth-and first-order equations of magnetostatic equilibrium.It shows that in those regions with stronger magnetic fields both gas pressure and temperature become lower.As far as the density is concerned,it may get higher or lower,depending upon the actual non-axisymmetric structure of magnetic field in sunspots.In the former case,the increase of density and the decrease of temperature will both bring about a decrease of brightness.In the later case,the changes of density and temperature have opposite effects on the brightness.Under the present model,however,it turns out that the decrease of temperature always predominates over that of density.We conclude,therefore,that dark penumbral filaments are associated with strong magnetic fields.