  We investigate sharply outlined features recorded in solar magnetic field
tracers. It is shown that the magnetic boundaries of a sunspot do not coincide
with the photometric ones. Moreover, there is no clear magnetic boundary around
sunspots. Thus, the widely accepted concept of a magnetic tube with clearly
pronounced borders is not always correct and should be used with caution. It is
also shown that even in the periods of complete absence of visible spots on the
Sun, there are magnetic fields over 800 Gauss. The nature of these strong
magnetic fields remains unclear; they may originate at relatively small depths
under the photosphere.
